30mm Diameter 10x magnification. 5mm diameter LED light. 30mm diameter integral 2x optical glass lens. Powered by 3x AAA batteries (not supplied). LED lasts around 40,000 hours under normal use. Battery life = 40/50 hours under continuous use. Compared to a conventional bulb the LED diode lives up to 1000 times longer with 90% less power consumption. Complete with plastic case with belt loop.