NS Novelties' Renegade Series, the Stamina Rings offer three distinct sizes to combine and experiment with, each boasting a varying thickness and intensity to suit your desires. Enhancing his erection by mildly grasping the base of the shaft to enrapture blood flow within the penis, he will experience a noticeably harder, longer lasting erection for prolonged ejaculation and increased stamina. Each ring is completely smooth all the way around, boasting a no-nonsense design that is wonderfully non-distracting during play. Completely body friendly, and virtually odor free, each piece in the set is made of Thermoplastic Elastomer which is compatible with any type of water or silicone based lubricant desired. Phthalate-free. Fits most.