Vintage Original Singer 221, 222 Peso Pluma Take-Up Completo #45822
It includes the mounting screw as pictured.Other than the featherweight machines it was used on a few other Singermachines as well (see below). The part number is 45822. 221,221K1, 222, 222K1, 301, 301-2, 301-3, 329K, 337, 338.