BAD556-LW Lightweight Billet Upper Receiver in 7075-T6 Aircraft Grade Aluminum GEN 2 Specifications: Precision CNC from Billet 7075-T6 Aerospace Aluminum Patent Pending Lightweight Design M4 Feed Ramp Machined T-Marks Laser Engraved Logo MIL-A-8625F, Type III, Class 2, Hard Anodized Flat Black Finish Compatible with TDP/Mil Standard AR Upper Receiver Parts  All Components, material, and packaging made in the USA Weight:  6.28 oz Light Weight (6.32 oz to 6.28 oz).  Compatible with FORTIS REV II Rail (with indexing tabs)