YH102 Aluminum Alloy 5mW 532nm Green Laser Scope 21mm Rail Gun Aiming Sight Color : black , Material : aluminum alloy , Suitable gun type : 21mm rail gun Laser wavelength : 532nm , Laser reaching range : 300m Length : 120mm , Height : 36mm , Weight : 144g Battery : 1 CR123AW (included) , Voltage : 3V Package includes :1 Laser scope ,1 Rat tail switch , 2 Bracket , 1 Battery , 1 User manual (English)