This Marlin manufactured second variation feed throat with three raised circular studs (two on the left and one on the right) is for the model 40 Coast to Coast semi-auto rimfire rifle which use the earlier lifter spring and not the later ejector/lifter spring and is in very good condition with light wear. This feed throat has the integral ejector that the 2nd variation lacks. (file photo)

Note: Model 40 rimfire rifles with the following years of manufacture and serial numbers have been observed with this part:

1971: 71474846