The Aero Precision M4E1 Enhanced is the premium tier of Aero's flagship AR-15. The Enhanced designation indicates a Geissele SSA or SSA-E trigger, BCM Gunfighter charging handle, and upgraded furniture compared to the base M4E1. The 16-inch mid-length chrome-lined barrel and M4E1 enhanced lower with integrated trigger guard and flared magwell provide the best out-of-the-box experience Aero offers. Type: Rifle Action: Semi-Automatic Caliber: 5.56x45mm NATO Capacity: 30 Year introduced: 2017, USA Weight: 64 oz Overall length: 32.5" Status: Active Intended use: Home Defense, Competition, Patrol Rifle