MDT’s Picatinny Rail with QD Sling Cup Mounts are compatible with the majority of MDT’s chassis systems, and install on the underside of the system’s forend to allow any picatinny-type accesoory to be used. These rails are precision machined from a solid block of 6061-T6 aluminum and are hard anodized for durability. Available lengths: 2.5”, 5”, and 6.5”. MDT 2.5" Blk Picatinny Rail with QD Sling Cup 102216-BLK