Bravo's KMR Alpha is constructed of aluminum with a hardcoat anodized finish for corrosion resistance and is free-floating. Its interface system was developed to work in parallel with the current picatinny system. This rail system allows for a larger range of modularity offering four different offset mounting positions between traditional 3,6,9, and 12:00 positions. Included is a BCM KeyMod sling mount . This model has a black finish and is 13" long.