The MAR-L MLC utilizes the LMT patented MRP(Monolithic Rail Platform), the only true monolithic rail system, milled from a single high-grade aluminum forging and uses two locking bolts to secure the barrel in place. The MRP technology engages the barrel extension at a full 360 degrees and allows for easy barrel removal while minimizing point of impact shift. The MRP platform is capable of accepting compatible barrels with different calibers and lengths.