Berges® Spring tension Pulley type F300b for use with wide belts type CW-b 51 and adjusting pulley R300b. Diameter of 305mm with length through bore 185mm, die cast aluminum sheave faces with steel slide hub. Identified by casting numbers x and x, one spring; castings used on other series of pulleys.. Maximum shaft diameter 48mm with standard bores listed for sale, alternative bores are available contact TVT for non-standard bore quotation.