Gates K070680RB Blue Racing Micro-V Belt Belts are precision ground, not cut, so they fit the pulley with absolute perfection 7 Ribs, .947 inch (24mm) top width, 68.06 inch (1729mm) effective length, 68.626 inch (1743mm) outside circumference High-modulus, low-stretch polyester means Herculean strength for high load-carrying capability Aramid reinforcement in a patented EPDM compound for three times the heat resistance and durability of standard belts Patented EPDM compound gives Gates Racing belts extended service life