This laser calibrator is made of high-grade aluminum alloy, offering lightweight construction, high strength, corrosion resistance, and long service life. It includes a full set of accessories for immediate use upon arrival. Features: - Constructed from high-grade aluminum alloy for durability and reliability. - Infrared laser output provides bright, clear, long-distance visibility to support precise calibration adjustments. - High-precision, adjustment-free design enables convenient and accurate alignment using laser guidance. - Simple, streamlined battery compartment design with twist-off tail cap for easy access and practical operation. Usage Instructions: 1. Measure the inner diameter of the tube and select the appropriate adapter (eight small black adapters included). 2. Use a cross-head screw tool to attach the adapter to the rear of the collimator tube. 3. Ensure the collimator body remains straight by securely tightening both the battery compartment and power switch. 4. Tighten the adapter and insert the rear tube into the target tube. Position the switch facing upward during insertion. Secure the device and proceed with calibration using a sight or scope. 5. Adjust the sight or scope until the laser dot aligns parallel with the collimator’s reference beam for accurate calibration.