4 PCS. BOBBIN WINDER TIRES O RING FOR SINGER 201 201-2 223 237 239 258 301 4 Pcs. Brand new Universal Bobbin Winder Spindle pulley rings ( Bobbin winder tires). THIS IS THE MOST COMMON BOBBIN TIRES. Tire Thickness - 9/32" Inside Diameter - 9/16" Outside Diameter - 1-1/8"