The LMT Modular Ambidextrous Rifle System (MARS) lower receiver offers ambidextrous controls to include: selector, magazine release and bolt catch and release. An enhanced flared magazine well and ambidextrous magazine and bolt catch mechanisms are machined directly into the receiver and have been designed to function as ergonomically as possible. This lower receiver is designed with several unique LMT features to further enhance its durability and versatility. These features are: Two-stage trigger group, winter trigger guard, ergo grip, QD endplate, and SOPMOD buttstock.