These are flat belts which are equipped with teeth on the inside (or on both sides) and reinforced with fiber. The thread is creased into a helix, thereby ensuring high belt strength. Toothed belts are used in high-performance units. It belongs to drives whose speed is transmitted synchronously, ie without loss of speed and with a constant gear ratio. Unlike V-belts, toothed belts eliminate the risk of slippage. Against chain drive, they also significantly reduce noise, are maintenance-free, light and oil-resistant. Belt teeth are designed to fit perfectly into the pulleys and reduce friction. The body of the belt including the toothing is made of a neoprene (polychloroprene) or polyurethane blend. Neoprene belts usually contain glass fiber, polyurethane belts are usually reinforced with steel fibers.