The unique hourglass shape grips tighter in the 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 stretching sensation.