This Marlin manufactured rear sight measures between .275" high and .325" high, has a .080" wide elevator groove and is for the Glenfield model 75 semi-auto rimfire rifle. This rear sight is in very good condition with light wear. (file photo)
Note: Marlin Glenfield model 75 rimfire rifles with the following year/serial number have been observed with this part:
1974: 26286232
