Developed through extensive laboratory and actual road mileage testing, this unique rib profile has been specifically Dayco® engineered to conform to high mileage, worn or misaligned drives without a sacrifice in quiet, long-lasting performance. Constructed with Aramid reinforced EPDM compounds, the belt delivers more than OE required quality...it delivers the solution to troublesome drive problems. Dayco® Poly-Rib® Belts meet or exceed SAE J1459 and SAE J2432 specifications.