This Marlin manufactured rear sight is approx. .380" high and has a .080" - .090" wide elevator groove and is for the Glenfield model 25 bolt action rimfire rifle. This rear sight is in very good condition with light wear. (file photo)
Note: Marlin Glenfield model 25 rimfire rifles with the following year/serial number have been observed with this part:
1974: 26630260
1976: 24633438, 24655014
1977: 23687531
