Picatinny Rail Mount for Ruger Mk I, II, III, IV and 22/45

Ruger MK II/III/IV Picatinny Scope Mount Rail by Majestic Arms
Low Profile Does Not Interfere with Iron Sight Picture!
  Precision machined, true Mil-Spec Picatinny Rail for mounting a scope, red dot, or laser on your Ruger MK Pistol. Fits Ruger Mk I, II, III, IV and 22/45 factory pattern screw holes. Screws included. Anodized flat black for no glare. Compatible with Weaver or Picatinny style rings.
  Rear is gracefully machined to blend with the factory adjustable rear sight (see photo).

Please note that during installation, the smaller screw needs to be installed in the hole closest to the rear sight.

E. Arthur Brown Company, Inc
4088 County Road 40 NW, Garfield, MN 56332