Less then 4 grams of weight, and this small tool is your insurance for battery condition on heli or other models. Selectable switch to choose your battery pack 4.8 or 6v.Very Bright leds to insure perfect visibility.Very low power consumption, not to draw too much current.Flat and very easy to mount. Just place it near your canopy screen, or on the fuselage, Boom, Under wing and you can be sure you are ready to go.