Only 4" long, weighing barely 1oz. and only 3/4" in diameter, you'll hardly know you're carrying it - until you switch it on - when it delivers either 220 lumens (high) or 20 lumens (low). That's a lot of output for such a tiny flashlight, and the secret is in the special ICR10440 rechargeable Li-Ion battery. As a bonus, this light also has a variable focus (flood to spot) lens. Comes equipped with a special charger and a cable. Plug the cable into any USB power supply or computer USB port to charge the light. This one is truly unique.