Submersible to 100 meters. Recoil LED technology directs the lamp rearward, into the reflector where 100% of the emitted light is captured & projected forward in a collimated beam. LED lamp offers durability, long service life, and long battery life compared to filament bulbs. Requires three (3) C-cell alkaline batteries (not included). Tested light output is 56 lumens with 43 hours of battery burn time.