Vintage Singer 15-91 bobbin winder assembly. This assembly comes with the longer return spring that is used on the 15-91 (potted motor), it is also compatible with the 15-90 and other models 15s that use the #125324 belt guard but you may need to shorten the tail on the spring. Mounting screws and springs included. Very nice vintage condition, the chrome is bright. The bobbin winder tire has been replaced. Original, genuine Simanco part #125327