all your laser types use batteries-the only other option is to use an optical- but the absolute best way is to SHOOT THE FRIGGIN THING- you're not going to get around it and start at 25 yards, get it centered, and then drop back to 100- your bore sight,is good only to get you on the paper- lots of people think just b/c it's boresighted, it's going to be centered when you go to shoot- well, news flash- it AIN'T the way it works- all kinds of things come into plaY- REMEMBER TO TAKE OUT THE SPUD OR BORESIGHTER BEFORE FIRING- there's been more than 1 gun turned into art b/c of this over the last couple of years