Function: do calibration tool: this 12 GA laser sight can be used as a do calibration tool to provide an accurate reference of do zero adjustment and calibration. Provide clear do calibration points: This 12 GA laser boresighter provides bright and clear do calibration points. (laser class IIIA, less than 5 mW) Scope of application: 12 adapters can be used do calibrate the 0.177 do 12GA hunting tool, which can be perfectly compatible with most hunting tools. Aluminum Alloy Material: This 12 GA laser sight is made of aluminum alloy, which is lightweight and durable. Good workmanship: exquisite workmanship, beautiful appearance, portable size, providing a great user experience. Specification: Article type: laser sight Product material: aluminium alloy Weight: approx. 160 g / 5,6 oz Maximum output power: less than 5 mW Length: approx. 162mm / 6.4in Battery information: 1 x 3V CR2 800mAh lithium battery (this battery cannot be charged) (supplied with matching battery) List of packages: 1 x Laser Sight 1 battery 1 x Screwdriver 1 x Hex Wrench 12 adapters 6 x mounting screw Note: Laser products should not be exposed to the eyes. Do not place the product in a damp place as this will damage the product. Do not use this product do uncivilized and unethical behavior, such as disturbing others at night, threatening public safety, etc. Do not bring the product do zoos, stadiums and other places where the use of a laser pointer is prohibited. It is not allowed to drive air vehicles. Disruption of public order and security will involve crimes. It must not be disassembled and disassembled by yourself, as well as shoot directly into the eyes and flammable materials. The laser lighting time should not exceed 2 minutes; No more than 1 minute in summer or when the ambient temperature is high. The laser indicator should not be hit or hit to prevent damage to electronic components. After installing the battery, press the switch to work normally. After installing with the appropriate adapter, it can be used do calibration.