Features A. Low profile, Compact, Lightweight and Portable design lasersight for pistiol. B. Easy operate. On/off press-button switch on both sides. C. Windage & Elevation are adjustable. D. Standard Picatinny rail, can be installed other devices, such as gun flash light. E. Quick disassembled picatinny mount, fit for universal 20mm weaver rail. Read more This laser scope includes 3 screw holes, can be adjusted to a proper position for your guns. Red Laser：Visible up to 100 meters at night. Green Laser：Visible up to 1000 meters at night. Anti-loose battery cover, much more reliable for using. Read more Read more 1. Loosen the mounting screw, then you can push the rail mount. 2. Align the lock screw into rail mounting slot and install the laser sight on the firearm. 3. Tighten the screw to finish the installation. Read more WARINIG Before beginning the adjustment process, insure that your weapon is unloaded and there is no ammo in the chamber. During laser alignment make sure to always keep your weapon pointed in a safe direction away from others and never place your finger on the trigger. Angeebin Laser Sight for handgun or rifle Packing List 1 x Laser Sight 4 x LR44 Battery (4) 1 x Battery Cover unlock Key 1 x H1.5 Allen Wrench 1 x H2.5 Allen Wrench 1 x User Manual Direct viewing of the laser is hazardous to the eyes. Never point laser beam at a reflective surface. Never point laser beam at a person. Do not allow children to use laser sight unless under adult supervision. Read more