YHMA(R) is very pleased to offer their flagship BLACK DIAMONDA(R) Specter XL Top End. The Black DiamondA(R) forearm bridges the gap between the upper receiver and handguard and is marked for position on all 4 sides. YHM's diamond pattern in the hand guard reduces weight and blends perfectly with our diamond fluted barrels. YHM-7820-8 Forged 7075-T6 Flat Top Upper Receiver with M4 Feed Ramps and "T" marked Forward Assist Includes Charging Handle Includes Bolt Carrier Assembly 16" 4140 Steel Barrel, Heat Treated to RC 25-32 Diamond Fluted to Improve Rigidity and Aid in Barrel Cooling Threaded to tak Mfg: Yankee Hill Machine Co., Inc.