Enduro Flex is a flexible resin that cures to a hardness of 80 shore A (firm rubber feel). It is highly tear-resistant and durable for long-lasting parts. Can be used for making semi-rigid molds, but mold release must be used both when casting Enduro Flex and when you cast material into a mold made with Enduro Flex. Also perfect for urethane bushings, cement stamp pads, or firm rubber fishing lures.