Cheap products without testing on the market , Attention!!! If I could, I would not give any or a minus star , A defective tensioner of Autodoc/Ridex has after 1700km the function stopped and thus caused an engine damage of 12500.-€ . Autodoc refuses to pay the damage in full . A , ordered by me , to determine the damage and cause , is doubted and the invoice not settled . Usage failure for half a year , not he still words about Autodoc.A strange legal action!!! The spare parts do not go through any testing during production, otherwise this part would have been noticed….Maybe ?? One thing Autodoc has done after all……. they sent me a new tensioner, now only the right engine is missing.