Instructions:
1. Install battery into the boresighter. Make sure the two position lines are aligned.
2. Choose the proper adapter(insert) that fits the barrel of your firearm.
3. Install the adapter at the small end of the boresighter, then tighten the screw to expand the adapter, and make sure it fit in barrel firmly.
4. Insert the small rod of the boresighter into the barrel of your firearm. Make sure the boresighter is inserted deeply enough until it is sung with the opening of your barrel.
5. After you press the button, a small red or green dot will be emitted. And then you can adjust your scope's windage and elevation so that the crosshair stays on the red or green dot.

Warning:
Before zero your scope, make sure that the firearm is unloaded and the muzzle is pointed in a safe direction.
After the firearms is adjusted, make sure to remove the boresighter and adapter from the firearm.
Keep boresight light beam away from eyes.

Specifications:
Weight: 1.65oz
Material: Aluminum.
Big end Diameter: 0.8".
Small end Diameter: 0.169".
Length: 6.57"
Shortest barrel available: 1.95".
Light Color: Green.
Wavelength: 532nm.
Max. Output Power: ≤ 4.5mW.
Light class: IIIa.
Batteries type: CR2 3V 800mAh, non rechargeable.

Packing List:
1 x Boresighter
2 x CR2 battery (800mAh each battery)
2 sets Adapters (2 packs)
1 x Screwdriver
1 x Instructions