Unique hourglass shape grip tighter int he middle where you want it most when stretching. but with a soft grip. The ends are thicker-won`t dig or pinch. Inside are two thin raised rings that keep this stretcher where you put it. SQUEEZE is made from FLEX-TPR so it`s lightweight and compact but still packs a punch. Unlike silicone. FLEX-TPR has a completely different feel for an entirely new stretchin` sensation.Size Height: 2/ 5.08 cm Outside Circumference: 5.5 - 6/ 14.02 - 15.24 cm Inside Circumference: 3.5/ 8.89 cm