Gates K050336RB Blue Racing Micro-V Belt Belts are precision ground, not cut, so they fit the pulley with absolute perfection 5 Ribs, .667 inch (17mm) top width, 33.75 inch (857mm) effective length, 34.315 inch (872mm) 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