I got one the other day - not sure which one it is but it has three AAA cells. Local outdoor was doing a special offer of one if you bought a north face duffel bag. It's slightly small then the one shown above. To say I'm impressed is an understatement. I spotlighted a fox the other night at 150 yds when out for a walk with the dogs. Plenty of light to tell it was a big dog fox and more than enough light to shoot it by. If only I had had a rifle with me.
It just takes a single AAA, has three power levels, and on highest level it has a 40 yard beam. Used it in anger last year when shot a buck right at the end of day. I needed the spot to find it in long grass - it had run 30 yds and then low power to gralloch it by. It lives in my shooting coat.