Value Collection 20MP012-6FA-3/1 Timing Belt Pulleys; Pulley Type: Hub & Flanges; Number of Teeth: 20; Outside Diameter (Decimal Inch): 0.4890; Material: Aluminum; Pitch Diameter: 0.509 in; 0.509 mm; Face Width: 0.26 in; 0.26 mm; Flange Diameter: 0.6