Attach receiver-style target sights to your favorite rifle without drilling and tapping. WR fits Weaver-style bases. Once sight is mounted to base, the entire unit may be removed and re-installed without loss of zero. Pre-drilled side mounting plate accepts Redfield Palma, Warner, Zelenak and other sights. Mounting plate is adjustable for vertical and horizontal position. Mfg: Lipski SPECS: Steel, matte black. Adapter base 2.25" (5.7cm) long, .90" (23mm) high. Threaded 10-32. Weighs 3.1oz. (68 g).