These belts have the same features as the belts type S, but with extra rubber protection cams on the top side. The flattenings of the rods lie between 2 rubber cams, so the product to be sieved will not be damaged by the rivet heads. Another advantage is that the rods do not touch the rollers on the return side. This prevents wear on the rollers and the rods and allows the web to run more smooth with lesser noise.