ErecAid Tension Bands, manufactured by Timm Osbon, are patented tension rings used for men with Erectile Dysfunction. Designed for use with an ED Pump, these Penis Rings are medically engineered for safety, performance and comfort. The unique upper extruding bumps press against the veins that maintain the erection and the lower urethral notch allows for ejaculation. These Timm Osbon Tension Bands should be replaced every six months, pending usage. These tension rings come in three tensions and two sizes. Features: These patented tension rings are medically engineered for safety, performance and comfort. MThe rings may be used individually or in various combinations to maintain an erection created by the Vacuum Pump.