BCM has made a name for themselves recently when it comes to AR-15 parts and accessories. All of us here at Full Metal Jacket use BCM accessories on all our firearms. 

The MCMR MLOK covers feature an ultra-slim and radiused surface to allows a "round" handguard feeling, from an Octagonal profile. Aggressive Non-Slip or Non-Reflective surface. Ventilated for cooling. Can be installed in either direction. Can be cut to any length, depending on users requirements..