Sealey VS027 Brake Fluid Tester

Comparative electrolytic type tester.
Checks moisture content of fluid by resistance to electric current.
Easily calibrated using new brake fluid.
Audible test cycle with three LED read-out.
Just insert probe and press button for immediate result.
Works on DOT 3, 4 and 5.1 specification fluids.
Uses 9V battery (not included).