Before installation, always use an alignment rod to verify proper setup of the entire system. Clean all surfaces thoroughly and ensure the muzzle device is properly torqued (15-25 ft-lb) and secured to the barrel with Rocksett. Make sure the muzzle device sits squarely against the shoulder. Note - using this system on a Q can may void your warranty - proceed with caution. When bipoding the suppressor, confirm that threads and tapers are clean, then torque it to 10 ft-lb. Double-check alignment before use. Enjoy with confidence. 17-4 PH H900 Compatible with Atlas and Atlas XL Compatible with Plan B The Atlas adapter has exceeded the limit by approximately 0.05 inches Atlas XL adapter does not experience overrun Black nitride coating with a surface hardness of 67 HRC