A very simple and easy unit to compare conductivity of different solutions, acids or salts. Dip the probes, press the button and note. The conductivity can be compared in 6 levels. Red LED gives a quick visual comparison. Stainless Steel probes 0.08" (2mm) dia. x 3.25" (80mm) L. Total length with probes 7" (180mm). Body 3.5" (90mm) L x 2.25" (60mm) x 1" (25mm) Thick. Requires 2 AA batteries, not included.