This is a folding leaf rear sight for standard rifles. It appears to be a reproduction of the Lyman 16B which was issued on standard rifles (24” and 26” barrels) from 1954 thru 1963. It adjusts from 0.345” to 0.445” and remains in very good condition.
We use the NRA Modern Gun Condition Standards Grading System for grading part conditions. You can read about it HERE
