NEO-STRETCH ballstretchers fit and feel amazing. The same shape as old-style neoprene ballstretchers same thickness but made of our super-soft stretchy silicone. It won't strangle your sack wears longer for more stretch more play... NEO-STRETCH keeps those nuts down in their sack. All all three styles have a fat lip around the edge so this one will not dig into your sack. Unlike neoprene NEO-STRETCH is rubbery stretchy and feels like its part of your sack... NEO-STRETCH SHORT fits any sack even high-and-tights. Safe with all lubes this toy will not pinch or cause the burning feel some get using neoprene on their sack. And no possibility of allergy because this is 100% silicone NEO SHORT is a 1.25-inch shorter ballstretcher that will fit any sack. Can be stacked as you grow. All are a little under 1 inch inside diameter with a slight swell in the center to squeeze you more where you need it most.