Features Standard single-channel model features open/closed LED indicators. Uses electronic inductance to accurately signal when points break. Very compact form factor: 3.125" (79mm) wide x 5.5" (140mm) long x .75" (19mm) high. Completely safe as it does no use any high voltages (4.5V max test voltage). Comes ready to use with a 9V battery. Great for ultralight engines, motorcycles, race cars, outboard motors, or any other single-mag engine.