This Ruger manufactured rear sight is for the standard model Mark I semi-auto pistol and is in very good condition with light wear and a few specks of rust. (file photo)
Note: Ruger Mark I semi-auto pistols with the following serial numbers have been observed with this part:
No Prefix: 127144, 129129, 166765, 210887 & 451514
12-11122
17-33228
