All components are rigidly mounted on a molded casing covered with a reinforced colored ABS plastic plate. Minimal vibration and well-balanced rotating arm give years of trouble-free operation. Max stirring capacity 1 liter. Minimum speed: 100rpm. Maximum speed: 800 to 100 rpm. 110/115V, 50/60 Hz power supply. 5.4"diameter x 2" height. Each stirrer comes with 1" long x 3" diameter Teflon coated magnetic stir bar and instruction manual.