Precision machined out of 7075-T6 Aluminum, the ARAK-21 lower receiver is purpose-built to match the ARAK-21 upper. A fantastic juxtaposition of smooth angles to the upper's angularity, the 21's lower receiver smooths the ARAK out whilst showcasing tiny ball end-mill machining in complex curves. The ARAK-21 lower receiver accepts all standard AR-15 lower receiver parts. Use any grip, trigger, magazine release, or pins you want! Note- The ARAK-21 lower receiver will not function with a standard AR-15 upper receiver. The ARAK-21 lower does not feature a buffer retaining pin.