Master Series Silver Hex Heavy Duty Cock Ring and Ball Stretcher. Designed for a tight fit for long lasting erections, this nut is definitely one for the toolbox. Made from firm yet flexible Thermoplastic Elastomers TPE, so it gives just a little yet still remains strong. The hexagonal shape adds a unique look to your cock, while helping you maintain an erection for extended sessions. Hex can also be worn as a ball stretcher. Use your imagination. It is your domain.