New in box LMT Defense MARS-L AR-15 in 5.56mm, part # CQBMLK16-MARS. Utilizing the LMT® patented Monolithic Rail Platform, MRP™. The only true monolithic rail platform, milled from a single solid piece of aerospace aluminum forging. It utilizes two locking bolts accessible from the side of the receiver to lock in the barrel extension. This patented technology engages the barrel extension for a full 360 degrees around the extension and makes the barrel removable within seconds with a return to zero of the same barrel. One receiver can utilize numerous barrels of varying length, material, and caliber. The upper receiver has 14.5″ of uninterrupted 1913 picatinny rail on the 12 o’clock position. The remaining 7 sides provide M-LOK compatible attachment points. Monolithic rail platform barrels utilize a low profile gas block and straight gas tube. They possess proprietary coating and are cryogenically treated for long term durability. The MARS-L ambidextrous lower receiver features LMT® ergonomic textured grip and SOPMOD stock, and the ambidextrous features include bolt catch, magazine catch, and safety selector. As with all LMT® lower receivers, the extension tube is coated with dry film lubricant. This weapon system comes complete with 3 grip panels, one magazine and owner’s manual.