This Lyman manufactured No. 1A folding tang peep sight with locking lever and small turn down peep is marked on the underside of the base with a "WS" indicating that this sight is for the Winchester model 1890 & 1906 takedown slide action rimfire rifles. The overall condition is very good to near excellent retaining most of its original blue finish with light wear and a few freckles of rust staining. The mounting screws are not included.  (file photo)