Stretch to Fit Most Bottles The rubber material and patented grooved-ring system allows for stretch and a non-slip fit. Baby-Safe Silicone for Teething The FDA-approved, food-grade material allows teething and chewing. Dishwasher Safe This rubber is resistance to heat. Just throw the TipMeNot in the wash with the bottle. Prevent Bottle Leakage and Nursing Spills No more bottle rolling off your little one’s chest and falling to the ground. But, if it does, it won’t leak.