Tension Ring Size B Pink Large High Tension Osbon ErecAid 1612- 1 Each Size B- Large with inside diameter (22mm) 0.875 Inch Pink Color- High Tension For Use with All Osbon ErecAid Manual and Battery ErecAid Pumps Models Medically Engineered tension Rings for safety, performance and comfort Unique upper extruding bumps are positioned to press against the veins that maintain an erection