The category covers serpentine and V-belts, idler and tensioner pulleys, complete tensioner assemblies and the kits that bundle a tensioner with its pulley and belt.
About 3,500 listings sit here, split between belts and the pulley and tensioner group. GM, Ford, Mopar and ACDelco all appear, and both the belt alone and the full tensioner kit are listed, which matters because a worn tensioner will destroy a new belt within a few thousand miles.
Belt fitment is decided by rib count, effective length and cross-section — and by whether the vehicle uses a stretch-fit belt with no tensioner at all. Rib count is the number that catches people out: a six-rib and an eight-rib belt of the same length are not interchangeable, and the difference is only visible if you count the grooves. Check the rib count, the length and whether the listing is a belt or a kit, and inspect the tensioner and idler pulleys for bearing noise before fitting a new belt.
