Thermoplastic Rubber TPR is a class of polymers, the characteristics of which mimic many of those of Silicone hygienic, soft, pliable, durable, non-porous. The sleeve measures 5.5 inches long. They are made using phthalate-free, non-toxic materials Thermoplastic Rubber TPR. Safe and pure phthalate-free as well as recyclable. A water-based lubricant is recommended. Always clean before and after use.