This is the same trigger mechanism used on ArmaLite AR-10* and M-15 rifles. The ArmaLite Tactical 2 Stage Trigger set provides crisp and reliable trigger control for increased accuracy and repeatability. 1st and 2nd trigger stages are set at approximately 3 and 5 lbs respectively for a safe yet precise trigger setting. Both stages are adjustable. ArmaLite Tactical 2 Stage Trigger Set includes all components needed and installation instructions.