The MFR rail systems from Daniel Defense incorporate the M-Lok attachment system, offering remarkable weight savings along with enhanced cooling, ergonomics and modularity. All of this is achieved while maintaining the robust strength and durability that Daniel Defense is known for. The rail features M-LOK attachment points in seven positions, complemented by an uninterrupted 1913 picatinny rail on top. Integrated ambidextrous sling swivel attachment points are found on both the left and right-side rails for added convenience. Its advanced bolt-up system increases strength and reduces the rail's overall diameter, improving control while using the bolt-up system barrel nut. Standard anti-rotation tabs make installation and alignment a breeze. The MFR is compatible with pinned low-profile gas blocks across pistol, carbine, mid-length and rifle length gas systems. Lightweight free-floating barrel design Steel barrel nut Continuous mil-spec 1913 picatinny upper rail M-LOK attachment available at seven distinct positions Configurable sling swivel attachment points Bolt-up mounting system with patent protection Military specification grade 8 fasteners