The OPTIBELT ZR Series XL Profile Timing Belt TOP Layer consists of a flexible, high-quality chloroprene compound, a very flexible tension cord made of fiberglass, and a protective, abrasion-resistant fabric. Teeth are made of shear-resistant and wear-resistant rubber compounds that form a belt back and a unit. Certain levels of oil, heat and cold resistance are standard features of ZR timing belts. Wide range of performance Low bearing load High level of flexibility Operating temperature range: -30 → +100 °C