Igwebu le-CR(Chloroprene Rubber), enye yenjoloba yemvelo evimbela umlilo, ngoba ifaka i-chlorine, yona ngokwayo inomsebenzi wokucisha amalangabi nomsebenzi wokuvikela umlilo. Njenge-CR enezinto eziyinhloko, njenge-ejenti eqinisayo, i-ejenti yokugcwalisa, i-ejenti ekhihliza amagwebu, i-ejenti evuthuzayo enomsizi. wenza impahla yesipontshi.