The Solar System as seen from earth. This model shows the five planets and moon as Ptolemy described them in his famous book, "The Almagest". It describes accurately all the naked eye phenomena of our Solar System. The fact that most of the motions described by this geocentric system are incorrect cannot detract from the fact that to the unaided human eye all these incorrectly described motions appear correct. The use of the Ptolemaic model together with the Copernican model improves student understanding of the motions of the heavenly bodies. 14" high x 20" long. With fully-illustrated instruction book.
This 2XL/4XL size Fire Public Safety Vest has a solid lime and red lightweight polyester front area with Ultra-Cool mesh shoulders and back. This is a high visibility safety vest with an enhanced 4-point breakaway design which offers fast removal and also acts as a safety feature by preventing snags on debris, heavy equipment or machinery. Convenient all-season adjustability provides a comfortable and proper fit all year. The split design with contrasting colors makes identification easy when working in crowded environments. Reflective edging by Brilliant Trim enhance low-light visibility. Features include: ANSI/ISEA 207 compliance, Double 1-inch Vizlite reflective silver stripes and lettering, microphone clip/tab holder on left chest to enhance communication, pencil and/or pen pocket on left chest, and one large inner left lower pocket. The pocket doubles as a unique storage pack for the vest when not being worn. This is the ideal high visibility safety vest for policemen and other police officials when working in dangerous low light areas.
Lightweight solid polyester front with Ultra-Cool mesh shoulders and back. 5-point breakaway. 4-season adjustability allows for accurate sizing in any weather, even over bulky coats. Two 1" wide high performance reflective material with contrast. Brilliant Trim reflective edging improves low light visibility. Convenient left mic tab holder. Handy left chest badge holder & right chest name tag holder. Left chest pencil/pen pocket. Inside large lower patch pocket (when not in use, the vest folds into convenient storage pouch).
This Medium/X-Large size Fire Public Safety Vest has a solid lime and red lightweight polyester front area with Ultra-Cool mesh shoulders and back. This is a high visibility safety vest with an enhanced 4-point breakaway design which offers fast removal and also acts as a safety feature by preventing snags on debris, heavy equipment or machinery. Convenient all-season adjustability provides a comfortable and proper fit all year. The split design with contrasting colors makes identification easy when working in crowded environments. Reflective edging by Brilliant Trim enhance low-light visibility. Features include: ANSI/ISEA 207 compliance, Double 1-inch Vizlite reflective silver stripes and lettering, microphone clip/tab holder on left chest to enhance communication, pencil and/or pen pocket on left chest, and one large inner left lower pocket. The pocket doubles as a unique storage pack for the vest when not being worn. This is the ideal high visibility safety vest for policemen and other police officials when working in dangerous low light areas.
Lightweight solid polyester front with Ultra-Cool mesh shoulders and back. 4-point breakaway. 4-season adjustability allows for accurate sizing in any weather, even over bulky coats. Two 1" wide high performance reflective material with contrast. Brilliant Trim reflective edging improves low light visibility. Convenient left mic tab holder. Handy left chest badge holder & right chest name tag holder. Left chest pencil/pen pocket. Inside large lower patch pocket (when not in use, the vest folds into convenient storage pouch).
This 2XL/4XL size Security Public Safety Vest has a solid lime and black lightweight polyester front area with Ultra-Cool mesh shoulders and back. This is a high visibility safety vest with an enhanced 4-point breakaway design which offers fast removal and also acts as a safety feature by preventing snags on debris, heavy equipment or machinery. Convenient all-season adjustability provides a comfortable and proper fit all year. The split design with contrasting colors makes identification easy when working in crowded environments. Reflective edging by Brilliant Trim enhance low-light visibility. Features include: ANSI/ISEA 207 compliance, Double 1-inch Vizlite reflective silver stripes and lettering, microphone clip/tab holder on left chest to enhance communication, pencil and/or pen pocket on left chest, and one large inner left lower pocket. The pocket doubles as a unique storage pack for the vest when not being worn. This is the ideal high visibility safety vest for policemen and other police officials when working in dangerous low light areas.
Lightweight solid polyester front with Ultra-Cool mesh shoulders and back. 4-point breakaway. 4-season adjustability allows for accurate sizing in any weather, even over bulky coats. Two 1" wide high performance reflective material with contrast. Brilliant Trim reflective edging improves low light visibility. Convenient left mic tab holder. Handy left chest badge holder & right chest name tag holder. Left chest pencil/pen pocket. Inside large lower patch pocket (when not in use, the vest folds into convenient storage pouch).
This Medium/X-Large size Security Public Safety Vest has a solid lime and black lightweight polyester front area with Ultra-Cool mesh shoulders and back. This is a high visibility safety vest with an enhanced 4-point breakaway design which offers fast removal and also acts as a safety feature by preventing snags on debris, heavy equipment or machinery. Convenient all-season adjustability provides a comfortable and proper fit all year. The split design with contrasting colors makes identification easy when working in crowded environments. Reflective edging by Brilliant Trim enhance low-light visibility. Features include: ANSI/ISEA 207 compliance, Double 1-inch Vizlite reflective silver stripes and lettering, microphone clip/tab holder on left chest to enhance communication, pencil and/or pen pocket on left chest, and one large inner left lower pocket. The pocket doubles as a unique storage pack for the vest when not being worn. This is the ideal high visibility safety vest for policemen and other police officials when working in dangerous low light areas.
Pulley is high-quality impact-resistant, chip-proof injection molded, balanced wheel. Smooth, clean V-groove. Wheel diameter 2", 360 degrees swivel hooks-top and bottom. All steel blocks.
Aluminum pulley 37mm diameter. mounted in thick strong metal frame for clamping to benches or boards.
Aluminum pulley 37mm diameter. mounted in thick strong metal frame for clamping to benches or boards.
Aluminum pulley 50mm diameter. Mounted in a bracket on a rod.
Aluminum pulley 50mm diameter. Mounted in a bracket on a rod.
Rugged plastic pulley with deep V groves mounted on a metal clamp. The sheave is 50mm in diameter. Clamp can be mounted on surfaces up to 25mm thick.
Rugged plastic pulley with deep V groves mounted on a metal clamp. The sheave is 50mm in diameter. Clamp can be mounted on surfaces up to 25mm thick.
• ANSI 107 Class 3
• 100% Polyester pongee to provide wind resistance and slight water repellency
• Zippered front pouch and passthrough pocket
• Stows in zippered pocket with carry strap
• 2" AwareLite reflective trim.
• Available in 7 sizes (MD-5X)
ANSI 107 Class 3. Wind breaker. 100% Polyester pongee to provide wind resistance and slight water repellency. Zippered front pouch and passthrough pocket.. 2" AwareLite reflective trim. MD-5X.
Includes 12 PVC samples. Determine the mass and volume of each sample. The slope of the straight line that results is the density of the material. The attractive wooden holder allows the teacher to see immediately when all of the specimens have been returned!
Includes 12 PVC samples. Determine the mass and volume of each sample. The slope of the straight line that results is the density of the material. The attractive wooden holder allows the teacher to see immediately when all of the specimens have been returned!
• Durable, easy-to-move plus it's double-sided to your your message seen
• Curved sign deflects wind for added stability
• Holds two standard 36"H x 48"W corrugated plastic sign panels included
• Exclusive "Grip-Tip-Roll" system eliminates lifting and carrying
• Features wheels on both sides for increased portability
• Rolling A-Frames are rust-proof, durable and long lasting
Ready2Use Next Generation Large Format Rolling, Quick Loading, Roadside A-frame Style Sidewalk Sign with changeable message boards. Patented and patent pending features for unmatched user friendliness, portability, and affordability. Displays curved sign panels for strength and visual impact. Water filled for stability; can withstand freezing. Just Grip-Tip-Roll to move in or out without lifting/carrying to keep user clean and dry. Resists winds up to 30mph. Black letters and Red Numbers on white background. Displays up to 5 lines of copy on each side.
Includes
2 - 36"x48"x4mm white sign panels with tracks on one side of each board,
421 - 5" letters, numbers, and symbols
24 - 10"numbers
2-10" SALE/Special headers
• Durable, easy-to-move plus it's double-sided to your your message seen
• Curved sign deflects wind for added stability
• Holds two standard 36"H x 48"W corrugated plastic sign panels included
• Exclusive "Grip-Tip-Roll" system eliminates lifting and carrying
• Features wheels on both sides for increased portability
• Rolling A-Frames are rust-proof, durable and long lasting
Ready2Use Next Generation Large Format Rolling, Quick Loading, Roadside A-frame Style Sidewalk Sign with changeable message boards. Patented and patent pending features for unmatched user friendliness, portability, and affordability. Displays curved sign panels for strength and visual impact. Water filled for stability; can withstand freezing. Just Grip-Tip-Roll to move in or out without lifting/carrying to keep user clean and dry. Resists winds up to 30mph. Black letters and Red Numbers on white background. Displays up to 5 lines of copy on each side.
Includes
2 - 36"x48"x4mm white sign panels with tracks on one side of each board,
421 - 5" letters, numbers, and symbols
• Closed Lenses, economy eye guard.
• Made of polycarbonate material.
• Lenses are side vented to prevent fogging.
• Lightweight and shatter resistant.
• Low cost.
Closed Lenses, economy eye guard. Made of polycarbonate material. Lenses are side vented to prevent fogging. Lightweight and shatter resistant. Low cost.
In this program, concise explanations of the various types of precipitation provide students with insight into how rain, snow, sleet, hail, fog and mist form, as well as how the water cycle -- evaporation, condensation and precipitation -- constantly "recycles" water around the world. Students will also learn how the density of water changes in different states. See typical weather patterns across North America, and watch how a ski resort keeps slopes looking white. One of six volumes in the Weather Fundamentals DVD Series in the Schlessinger Science Library. Part of the Schlessinger Science Library in Action Collection. This title correlates to the National Science Education Standards for Earth and Space Science -- structure of Earth's system, Earth's history and Earth in the solar system. A Teacher's Guide is included and available online that features additional information on the topic, vocabulary words, discussion questions, follow-up activities and lists of recommended books & Internet resources. 23 minutes. Grades 4 to 7.
In this program, concise explanations of the various types of precipitation provide students with insight into how rain, snow, sleet, hail, fog and mist form, as well as how the water cycle -- evaporation, condensation and precipitation -- constantly "recycles" water around the world. Students will also learn how the density of water changes in different states. See typical weather patterns across North America, and watch how a ski resort keeps slopes looking white. One of six volumes in the Weather Fundamentals DVD Series in the Schlessinger Science Library. Part of the Schlessinger Science Library in Action Collection. This title correlates to the National Science Education Standards for Earth and Space Science -- structure of Earth's system, Earth's history and Earth in the solar system. A Teacher's Guide is included and available online that features additional information on the topic, vocabulary words, discussion questions, follow-up activities and lists of recommended books & Internet resources. 23 minutes. Grades 4 to 7.
• Lightweight 100% polyester oxford with PU coating
• Pocket slits on side with rain guard
• Ankle snaps and fly closure
• Class E (for ensemble) when worn without other ANSI compliant garments
• Class 3 when worn with a Class 2 or Class 3 upper garment
• Available in 2 colors and 7 sizes
ANSI Class E (ensemble) when not worn with other ANSI 107 garment. 100% Polyester woven oxford w/PU coating. 5.5mm. Pocket slits on side with rain guard. Snap ankle and fly closure. Class 3 when worn with Class 2 or 3 vest. AwareLite reflective trim.
To investigate the properties of lenses and to construct simple optical instruments. Kit comprised of the following: Two lamp holders, each in cast alloy shade with two axial slots. Complete with two meter 2-core cable and lamp. Shade has integral support arm which is clamped at right angle to the vertical rod, 165 mm long, fitted on heavy cast base, stove hammer finish. One each right and left hand cylindrical lamp shield of light alloy in matt black finish with slot parallel to the axis, size 190 x 60 mm, Height x Diameter. Two black plastic plates, 100 x 80 mm, with 17 equispaced parallel slots. Two black plastic plates, 130 x 80 mm, each with single and triple slits. Two metal support brackets, matt black finish with spring-loaded clips to hold the plates. Four black finish metal light barriers, height 80 mm. Ten Cylindrical Lens ( 8 plano-convex, and 2 plano-concave ), size 50 x 50 mm, Side x Height. Manual included.
To investigate the properties of lenses and to construct simple optical instruments. Kit comprised of the following: Two lamp holders, each in cast alloy shade with two axial slots. Complete with two meter 2-core cable and lamp. Shade has integral support arm which is clamped at right angle to the vertical rod, 165 mm long, fitted on heavy cast base, stove hammer finish. One each right and left hand cylindrical lamp shield of light alloy in matt black finish with slot parallel to the axis, size 190 x 60 mm, Height x Diameter. Two black plastic plates, 100 x 80 mm, with 17 equispaced parallel slots. Two black plastic plates, 130 x 80 mm, each with single and triple slits. Two metal support brackets, matt black finish with spring-loaded clips to hold the plates. Four black finish metal light barriers, height 80 mm. Ten Cylindrical Lens ( 8 plano-convex, and 2 plano-concave ), size 50 x 50 mm, Side x Height. Manual included.
Stamped steel base. Black enamel finish. Zinc plated, detachable rod. 6" x 9" base
Stamped steel base. Black enamel finish. Zinc plated, detachable rod. 6" x 9" base
Stamped steel base. Black enamel finish. Zinc plated, detachable rod. 4" x 6" base
Stamped steel base. Black enamel finish. Zinc plated, detachable rod. 4" x 6" base
A self-contained unit to measure and study refraction of light. Incident and refractive rays are easily seen and measured. Light rays air into water, water to air and water in water can be studied easily with the help of built-in laser, as a light source, which revolves and can be fixed at any point around a circular graduated scale. With leveling screws to level the water in the tank. Circular scale 160 mm ( 6-3/8 in.) Diameter.
A self-contained unit to measure and study refraction of light. Incident and refractive rays are easily seen and measured. Light rays air into water, water to air and water in water can be studied easily with the help of built-in laser, as a light source, which revolves and can be fixed at any point around a circular graduated scale. With leveling screws to level the water in the tank. Circular scale 160 mm ( 6-3/8 in.) Diameter.
Replacement Belt for Van de Graaf Generator
Replacement Belt for Van de Graaf Generator
Surgical stainless steel, No. 22, will fit handle (11452).
If you already own a checker, this replacement electrode will fit any checker.
If you already own a checker, this replacement electrode will fit any checker.