The LMT MLC MARS-L 5.56 Quad AR-15 Rifle is a high-performance rifle designed for professional and serious recreational use. It features a unique upper receiver known as the Monolithic Rail Platform (MRP) which combines the handguard and upper receiver into one rigid unit made from a single piece of forged aerospace-grade aluminum. This design offers superior strength and eliminates the possibility of POI (point of impact) shift when attaching sights to the handguard. The MRP upper also allows for quick and easy barrel changes with minimal tools.

The lower receiver is the MARS-L model, which is ambidextrous with controls for the bolt catch, magazine release, and safety selector on both sides of the receiver. The lower also features an LMT two-stage trigger, winter trigger guard, ergonomic textured grip, and SOPMOD stock.