While iron sights have always been able to get people on target, they're often considered less precise than other optics options, as well as getting in the way of seeing the target at extended range. The Ultradyne C4 Offset Sights fix this problem by providing an innovative sight picture based on the company's Dynalign technology. This Ultradyne C4 rear sight provides AR-15 shooters with a rear aperture that, when combined with a compatible front sight, offers what the company calls a "circle-within-circle" sight picture, allowing users to simultaneously observe a target while dialing-in their iron optics. Mounts to any MIL-STL 1913 Picatinny rail Made Mfg: Ultradyne Usa