TerraCycle's newest Idler is the Sport Series Idler which has been years in development. They wanted the same attributes in this idler the Elite Series Idlers have been known for but in a more economical package. With ballistic nylon side plates and an aluminum cog, these idlers should give years of trouble free service and improve most drivetrains that had stock non-toothed idlers. Size of the Idler is 2.75 inches with a 15 tooth aluminum cog. ABEC shielded bearings are standard.