This Remington manufactured magazine ring is for the model 12 slide action rimfire rifle and is in very good condition exhibiting a brownish gray patina with light wear and some specks of rust.  (file photo)

Note: Remington model 12 slide action rimfire rifles with the following serial numbers have been observed with this part: 351695 

12-A: 30310, 100823, 374065, 741138, 802984 & 806842

12-C: 303506, 408616, 409187, 500140, 597770, 600364, 607712, 640490, 663586, 722004 & 830348

12-CS: 225240