The Speed Shift Ring from Perfect Fit is possibly the most adjustable penis ring available on the market and is certainly the most versatile penis ring in the Perfect Fit collection. Designed to offer extra support to the penis and give the user a more rigid erection that can be held up to 30 minutes, the Perfect Fit Speed Shift Ring gives the user 17 different sizes to choose from ensuring that whoever is wearing it they will have a perfect fitting penis ring offering the exact amount of restriction needed. Thanks to the adjustability and versatility of this device it can be worn in numerous ways, either to secure the base of the penis shaft and restrict the corpora cavernosa ? the chambers in the penis that control the inflow and outflow of blood that create and release an erection ? or to restrict the penis shaft and secure the testicles. Unlike a standard penis ring, which are made from a solid loop of material, usually rubber or silicone, the Perfect Fit Speed Shift Ring is adjustable so it fits correctly and does not cut into the skin. With the addition of its quick release click-in fasteners, the device can be put on very quickly and removed in an instant. The Perfect Fit Speed Shift Ring measures 27cm in length by 1.3cm in width approximately. The loop locks into a range of sizes ranging from 11cm to 20.5cm in circumference. Made from TPR, The Perfect Fit Speed Shift Ring is safe to use with a variety of lubricants.