Leupold 183481 QR Weaver Base Set Quick Release Matte Black Steel Fits Nosler M21

Quick Release Weaver based on the familiar cross-slot design, both the QRW mounts feature a solid steel construction that has been extreme recoil tested. They offer universal cross-slot compatibility- they'll fit Weaver and Picatinny rails. A low-profile design offers a streamlined look and feel.