Riiiiiiiight. Call me a "naysayer" or what have you, but it doesn't take much to realize that a light costing less than the batteries inside probably isn't the smartest idea for a defensive weapon. But for the OP's sake, I really do hope it works out.
NRA Certified Pistol Instructor & RSO, IDPA Sharpshooter, Project Appleseed Rifleman
Member NRA, GOA, SAF, VCDL