PREMA Center-Over-Injury OTR Repairs are compounded and designed for use in today's Radial OTR Tires. The PREMA OTR Repair Units are designed for Heat Cure Applications, available only in cloth backed style, which provides extended shelf life. These Repair Units can be used for repairing Crown, Shoulder, and Sidewall injuries. Install PREMA Cloth Back repairs with PREMA Cushion Gum and PREMA Black Vulc Cement. (Heat Cure Only). Refer to the PREMA Radial Repair Chart for selection of the repair unit.