The POTENZduo, made of medical-grade silicone, ensures perfect coordination between the rings around the penis and testicles, providing a comfortably firm fit for increased sensitivity and a more intense erection. They can also be used to improve erections and maintain erectile function in cases of erectile dysfunction (impaired blood flow to the penis). Please refer to the enclosed instructions for use! FREE from plasticizers (phthalate & bisphenol A (BPA)) Medical-grade silicone Hypoallergen Size M Made with Love in Germany It prolongs erection and delays ejaculation. For penis and testicles