Blackhawk! Rail Mount Vertical Grip dramatically improves weapon control and heat management. Molded out of high-performance, fiberglass-reinforced polymer you know this vertical grip was built to be durable. It also incorporates redundant clamp screws for secure, reliable mounting. These clamp screws also have an adjustable fit to compensate for out-of-spec rails. Two different caps are included for custom length as well as an O-ring sealed compartment for tools, batteries, etc.