This Ithaca manufactured bolt spring is for the model M-66 12 & 20 gauge Supersingle lever action single barrel shotgun and is in very good condition with light wear and handling marks. (file photo)

Note: Ithaca model M-66 Supersingle lever action single barrel shotguns with the following serial numbers have been observed with this part:

12 Gauge: 17010, 30958 & 53451

20 Gauge: 51645 & 202920