Keeping tension on your timing belt is imperative for keeping everything turning to spec and running properly. If slop develops in your belt due to a worn tensioner, the timing belt can skip a tooth causing catastrophic damage and potentially ruining your cylinder head. The damper applies pressure to the tensioning roller, keeping the timing belt tight to the camshaft and crankshaft gears. Fits Volkswagen & Audi AWM 1.8T vehicles.