The AD-170 base is the foundation for several different mounts. Standalone it is a Surefire 951 Type weapons light mount. Alternatively it can accept several different risers to accomodate a variety of uses. It is precision machined from 6061 T6 aluminum and finished in hard coat T3 Mil-Spec anodize. It features the Patented QD Auto Lock Lever system to accommodate both in spec and out of spec rail systems.