If you have and older RugerA(R) MKI, MKII(TM) MK4 that's not drilled and tapped you can install this WEIG-A-TINNYA(R) Scopemount without making any permanent alterations to your favorite pistol. Remove the rear sight, insert the threaded dovetail filler and install the mount with the screws provided. Accepts all Weaver style rings and accessories and most Picatinny rings and accessories. 5-1/4" long, silver or Black, matte anodized finish, weighs 2.5 ounces. Mfg: Weigand Combat