just a tip. if you are in the army or any branch that wears ACU's and you drive a motorcycle, dont put your PV's in the outside pen pockets. yeah i should have known better but i put my 510 and 401, assembled in my pen pocket and about 5 min into my ride on the interstate i start to notice a burning on my forearm. i look down and notice a wet spot and it hits me, the auto batts are cooking the attys. it was bad enough that i had to pull over and rectify the situation. needless to say i think i burned up 2 attys. they still fire up but there is a nasty burned taste in both. i need to clean them out and try them again, if not then i really messed up 2 attys. live and learn! 8-o