This is a MARS-LS with quad MRP-L upper custom milled to a “Quad Nose” shovelnose piston system via D. Wilson. 

The cut op was excellent and this particular upper has a perfectly centered barrel. Barrel is a gen 2 piston unit with suppressor setting. Has seen 300 rounds.

BCG is the gen 2 piston with the enhanced Aermet100 bolt. These bolts are indestructible and extremely expensive ($500+). 

Everything else is factory LMT including trigger, charging handle, etc.

The utility of this custom operation is to allow the use of a longer monolithic upper that surrounds the gas block for added real estate, similar to the shovelnose, but utilizes 1913 picatinny instead of MLOK.