IsoMold CMR 4501 is a two-part polyurethane molding system. IsoMold CMR 4501 is mixed one-to-one by volume and cures at room temperature. IsoMold CMR 4501 cures to a medium (Shore A 45 ± 2), gray rubber. IsoMold CMR 4501 is used to make molds of detailed masters that do not contain undercuts. IsoMold CMR 4501 physical properties make it ideal for making concrete patterns and formliners.