Material: Housing sintered steel or grey cast iron GG20, lever St52, sprocket made of steel. This tensioning element, a continually-tensioning torsion element, prolongs the service life of chain and belt drives by at least 30%, and radically reduces maintenance and repair work. The unique operating principle of this spring offers a long tensioning distance, especially as the lever can be pre-tensioned by up to 30° in both directions. The permanent torsion force does not only automatically compensate the chain elongation, the rubber mounted element also dampens vibrations and shocks in the entire drive. Other advantages: chain track adjustable, rubber suspension, adjustable at an angle of 360º, tensioning pressure steplessly adjustable from 'normal' to 'hard'. Can be used for both tensioning directions.