Something you migth want to consider instead of the Surefire version. This one's at Tactical Tailor... "Energizer's Hardcase Tactical Helmet Light combines light weight, durability and function into one sleek high-tech package. Designed to mount on your helmet for hands-free lighting, the waterproof Hardcase Helmet Light provides four light modes: White main LED, blue LED, I­R light, and IR IFF strobe with a lockout switch to prevent visible light being turned on during IR operation. The package includes swivel helmet mount and vest clip with no need to buy anything else. The light can mount on either side of the helmet for left or right handed operation.

Operates on one AA battery (included)."