Brand new, never used/installed. Genuine Peloton Bike Idler Pulley with Tensioner assembly rod and installation hardware. SP-11, Tonic manufacturer bikes. Send questions, former Peloton master tech.

Belt tension assembly. If your bike is making a “rumbling” noise, or is not smooth in the cranks/pedals it could be a bad bearing in either the hub or the belt tension pulley assembly.