Timing (synchronous) belts The timing belts of sunyoung industry are made from cr, hnbr or pu, etc., which provide a synchronous transmission by utilizing the engagement between belt tooth and pulley, offer the following advantages: high transmission power, high efficiency, a wide range of speed ratios, low transmission noise. The belts are widely used across all sectors of industry, for example: the automotive industry, the textile industry, the chemical industry, the light industry, the metallurgical industry, machine tool and instrument manufacturing industries, etc.