neoprene (cr) and epdm rubber (epdm) with characters of v belt and flat belts, v-ribbed belt has soft and tough property as flat belt and tight and effective property as v belt. 1. transmission power so high that at the same condition its 30% higher than common v belts. 2. with tight transmission system, at the same transmission power, its occupied space is 25% smaller than common v belt. 3. flat and soft belt is suitable not only for transmission of small pulley but also for high-speed transmission with speed of 40m/s, besides its characteristics as slight vibration, few heat diverge and steady working. 4. anti-heat, anti-oil, anti-wearing out few elongation and long life