Dunlop SPA V-pulleys are manufactured from cast iron EN-GJL-200 UNI EN1561 and are black phosphated according to ISO 4183 and DIN 2211-3 norms. All pulleys are statically balanced for peripheral speeds up to 35 m/sec. Taper Bore V-Pulleys to suit all Wedge belts with cross section SPA (12.7mm). All Taper Bore V- Pulleys require the corresponding Taper lock bush (Sold Separately). Part numbers are identified by 3 letters (e.g. SPA) which represents the belt cross section, a 3 or 4 digit number (e.g. 250) the pulleys pitch diameter and a 1 or 2 digit number (e.g. 3) the number of grooves/belts to be run in the drive, for example SPA250/3.IMAGE IS FOR ILLUSTRATIVE PURPOSES ONLY. PLEASE REFER TO PRODUCT DESCRIPTION.