Wanted a laser for my blowback pistol, got the above for £10 from Ali express (green laser is more expensive), very pleased for the money. Torch is nice and bright and laser is easy to set up. On switch is right handed on, left handed off. Takes a single CR123a battery. Its is quite chunky at 75mm long,45mm deep, 25mm wide. Weighs in at 77g with a battery.