Rear sight w/ rail Allow 10/22A(R) to have similar sight picture to military type rifles such as the AR-15/M16 Rear sight has A1 style adjustments, with A2 aperture Rear sight now has 10 windage positions, allowing for much finer adjustments Rear sight includes integral scope rail for mounting optics Rear sight base is machine from 6061 T6 billet Finished with black type 3 hardcoat anodizing Rear sight comes with four Torx head screws for mounting Use with RugerA(R) 10/22A(R) Front Sight (100-007-029 or 100-007-239) Mfg: Nodak Spud Llc Specs: Fits RugerA(R) 10/22A(R) rifles. Includes four torx head screws for installation.