Its a great light, very defined beam with minimal spill. Compared it to the X300u and at 325 Lumens its brighter than the surefire at 500 lumens. Its hard to describe but the beam is very direct and intense... I think runtime is around 45-60 minutes IIRC. Just ordered another 300 body and a E1HT for my sons rifle. Ha! Now UW will have to upgrade...