Exceptionally designed for use with AR-15, M-16 and M4 style handguards. Picatinny dimensions allow for a wide range of accessory applications. Attach to handguard with screws and housing adaptors for quick and rock solid installation. Designed with swivel housing and complete with a swivel adaptor to allow for additional optional QD swivels or bipod installation. Will fit any style handguard: 16 or 20 inch BBL. Rail Length: 5 inches. Two rail set.