Pulleys are of primary importance for the operation of the engine. That is why these seemingly simple devices are, in fact, highly advanced parts which require computer-aided design, a proper choice of materials and the implementation of modern manufacturing processes. Our pulleys are based on Japanese bearings, which ensures safe and long operation. Extra attention should be paid to tensioner pulleys that are an attractive alternative to complete belt tensioners, which are very expensive, but in most cases the faulty element in them is the pulley.