Perkins v-belts, also known as vee belts or wedge belts 80109050, are designed to prevent alignment and slippage problems. With greater load, the belt will tend to wedge into the groove, providing better performance. Widely used due to the strength and reliability from fibre reinforcement. When replacing fan belts check the belt tension is correct, together with all the electrical connectors and the battery. Where engines have twin belts, check to ensure the belts are of a matched length.