This circa 1960 manufactured Lyman No. 66 receiver peep sight has the slotted adjustment knobs, steel base and is marked "Lyman / 66W88" which indicates that this sight is for the Winchester model 88 lever action and model 100 semi-auto rifles. The overall condition is very good to near excellent with light wear and possibly some oxidation staining. The mounting screws are sold separately and the box is not included. (file photo)
