Drive belt made to FSP specs., 1/2 X 99". For 600 series tractors. Kevlar corded belts, also called Aramid or extra-heavy duty belts are constructed of organic polyaramide fibers that are manufactured using complex chemical processes. **Interesting fact: Kevlar is the same material bulletproof vests are constructed with. Kevlar is used in PIX belts as a tension member because of its inherent stability and high tensile strength Cord