YHM is proud to offer our first Billet Lower Receiver. We originally designed a Billet lower that mimicked a standard (forged) lower receiver but after seeing the prototype production we decided to go with a receiver that was more stylized something that didn't look like every other AR-15 on the planet. It was this mindset that helped us arrive at the MODEL-57 and in turn this lower receiver. - These lowers were designed and are machined 100% in house from 7075-T6 aluminum (Billet) - Features over sized magazine well chamfers for easier magazine changes - Accepts All Generations of PMAG's - Accepts Mil-Spec Upper receivers - Built in oversized machined trigger guard - Fits all standard parts (except for a trigger guard) - Hardcoat Anodized matte black to Military Specifications or better - This lower still fits and functions with your standard upper receivers