Versatile instrument can measure RPM on a wide variety of engines from string trimmers to automotive. Reads engine revolutions up to 20,000 RPM. Built-in LED Flashlight which can be used while taking measurements. Backlit LCD display - Accuracy positive or negative 10 RPM. Picks up signal wireless or with supplied inductive pickup Great for use on a wide variety of engines,including: outboards, snowmobiles, motorcycles, small engines, generators, lawn equipment, ATV, automotive and more.