Manufacturer: New Frontier Armory
Model: Side Charging AR-9 Stripped Billet Upper with LRBHO — LAST ROUND BOLT HOLD OPEN
Caliber: Multi (will accept any barrels, bolts and caliber designed for the AR-9/45 style platform)
Weight: 13.6 oz
Other Specifications and Features:
**NOTE: Some rail systems that use anti-rotation tabs may need slight modification to fit this upper. It is designed for flush mounting rails and standard hand guards.
**NOTE: Not compatible with Colt 9mm Carbines
**When using this upper for a 9mm or .40 build you must either use a carbine buffer with our buffer spacer, or a 9mm LONG buffer. Not following these instructions could cause damage to the rear door of the upper that will NOT be covered under warranty**