Berges® Spring Tensioning pulley type F181sb interchange with Lenze® Simplabelt size 11.104.20.6.1. for use with wide belts type CW-b 28 and fixed diameter pulley, speed change achieved by changing center distance between sheaves. Diameter 120mm with length through bore of 108mm, one spring on each side of pulley for a total of two springs. Identified by casting numbers 11000308 and 11000326 stamped on pulley faces; castings maybe used on other series of pulleys. Maximum shaft diameter 28mm with standard bores listed for sale, alternative bores are available contact TVT for non-standard bore quotation.