Thruster is designed with amazing stretch, up to 3 times its size, it grips firmly but is super-stretchy and rubbery so feels great. The three humps create pressure points where you need them, and push you out for a bigger bulge. Flex-TPR safe, non-toxic and phthalate free Thickness .75 inch to 1 inch. Outside circumference 7.5 inches. Inside circumference 3.75 inches.