The unique quick detachable (QD) design stops the metal swivel body from contacting the gun. The close Machining tolerances provide smooth and silent operation. Developed at the request of the us military, these 1 1/4 inch swivels were designed to meet their strength and surface treatment standards. Mim (metal injection molding) construction for unrivaled integrity. Super-heavy-duty, made to military specifications. Dependable under the most demanding conditions. Set of two 1.25 inches swivels..