Two-piece clamp with single cross-bolt secures adapter to Picatinny/Weaver-style handguard rails so you have a front sling attachment point. MCTAR-06 has pivoting, 1A 1/4" wide swivel for direct sling attachment. Rubber coating on swivel prevents noisy, metal-to-metal contact. MCTAR-07 includes a fixed, dome-shaped stud that accepts your own, standard quick-detach swivel. MCTAR-08 includes a 11/4" wide, 360Adeg rotating, push-button swivel for rapid sling removal. MCTAR-08HD has heavy duty base and swivel that stands up to extreme tactical operations. 1A 1/4" wide, quick-detach swivel limits travel to prevent sling wrapping yet allows necessary movement. Mfg: Midwest Industries SPECS: Bases - 6061 aluminum, mil-spec hardcoat anodized, matte black; steel setscrew, matte black oxide. MCTAR-08HD - 7/8" (2.2cm) long x 13/16" (3cm) wide. Swivels/Studs - Steel, black finish. Swivels accept slings up to 11/4" (3.2cm) wide.