These belts are made of various materials such as leather, rubber, and canvas. They are commonly reinforced with specially tough material for strength. Because they are small, flat belts produce little bending loss when engaging the outer surface of pulleys. They also do not require grooves like V-belts, reducing wear and extending service lives. This means that if a flat belt breaks, the whole machine can be shut down to replace it without losing operation. This reduces downtime and production costs.