The URF-S is a billet upper receiver without provisions for a forward assist, it features faster access to folding back up sights and an over pressure gas relief for suppresser use. Type 3 hard coated in black. URF v2's over pressure gas relief vent is licensed from BATTLEARMS IP under U.S. Patent No. 8,910,406 Also new in v2 is LMT MARS receiver compatibility. 5 axis machined from 7075 T6 billet M4 feed ramps Engraved "T" numbers Over pressure gas relief vent for suppressed use 1913 picatinny Rail flat top Mil Spec Type III class II hard coat anodized Black Shell deflector Dust cover port machined into receiver Mfg: Forward Controls Design Llc