New SKF Timing Belt Tensioner Bearing. Genuine SKF Bearings. Auction is for a set of 4 x Bearings, 2 x Lock Nuts and 2 x Wave Spring Washers. Replaces Ducati Part Numbers 70240581A / 751832054 / 75183.2054, 74940081A , 85310021A. Fit Alloy Pulleys Only.