Material:100% EPDM, nature rubber, SBR Size:9", 15", 21", 31", 41" Pre-inserted stainless steel "S" hooks Material:100% EPDM, nature rubber, SBRSize:9", 15", 21", 31", 41"Pre-inserted stainless steel "S" hooksOffer expectional performance under any conditionWill not or lose elasticity after continuous exposure to the elemants and UV rays Rubber straps for liftimg