I need a bright flashlight to peer down a 40' oven at work. Also need to use it to detect thin spots in molded fabric parts, so it must be bright.

I'd prefer something small enough to hang off my belt, and using 18650 batteries. Bonus if I can have it spread as well as focus. I'd like to spend no more than $15 on it, if possible. Some of my coworkers have sticky fingers.