This FEBI BILSTEIN 17066 tensioner is designed to maintain the correct tension on your engine's drive belt. Proper belt tension is crucial for the efficient operation of accessories like the alternator, power steering pump, and air conditioning compressor. A worn or faulty tensioner can lead to belt slippage, noise, and premature wear of the belt and other components. Manufactured to high standards, this tensioner ensures consistent performance and longevity.