Listing is for one set of two replacement bearings for the original equipment cast steel Caroni idler pulley on the TC910 mowers. enough to rebuild one idler pulley. Why replace your idler pulley when you can replace the  bearings inside it. These bearings may not fit aftermarket pulleys that are riveted together!
Specifications
Two (2) High speed ball bearings
15mm ID X 32mm OF X 9mm Thick