This Winchester manufactured first variation trigger pin (.080" diameter) is for the first variation model 37 single barrel shotgun in 12 and 16 gauge only and uses the first variation trigger. This pin is in very good condition with light wear. NOTE: The first variation model 37 frame supports two larger .080" diameter pins (trigger pin and cocking lever pin) along the lower tang instead of the three slightly smaller .065" diameter pins (trigger pin, cocking lever pin, and the locking spring guide rod stop pin) which are used on the later second variation frames. (file photo)