Specifications  -Length: 123mm. -Weight: 144gram. -Reaching Distance: 980ft/300m. -Wave Length: 532nm. -Power: Less than 5MW. -With 2 20mm rail mounts(including one Dual 25.4mm Ring Mount). -Material: Aluminum. -Battery Model: 1pc 16340 Rechargeable Battery (not included)  Remote switch included.  -This durable all metal laser sight comes with tools to adjust windage and elevation to suit your needs. -The unit also includes an interchangeable switch which allows the user to press the unit to turn on or to use an attached remote to turn on the scope. -Prop up the scope using only a 20mm weaver mount or an 8 shaped 1" barrel mount.  How to Operate  -Fix the laser sight to a weapon. -Adjust the elevation and windage by twisting two small screws in the head with the hex wrench. -Turn them until the main laser overlaps with the scattered points. -Press the button to turn on the laser. -To change the battery, unscrew and open the back cover, then replace the battery.