These bobbins have holes in both sides. , steel bobbin compatible for singer featherweight Featherweight 221,221K,221K1,221-1,222,222K,301,301A , compatible for Kenmore: 49;Fit for Newhome: NLB , compatible for Bernina: 117, 217, 540, 640-2, 740, 750, 840-850, 940 and 950 , compatible for Alphasew: 221 Featherweights 221k, 221k1, 221-1, 222, 222k, 201 ,201A