The Half Twist Stainless features the revolutionary new Half Twist cap. One can drink from either of the two openings in the contoured mouthpiece, while the other allows air to flow into the bottle, providing a smooth, even outflow of liquid. The cap requires just a half turn to the left to open and a half twist to the right seals the bottle, watertight. There’s no need to ever remove the cap to drink. The cap is fitted with a medical-grade silicone gasket, which prevents leaks, spills, or drips. The gaket is easily removed to facilitate thorough cleaning of both the cap and gasket. The bottle is made from high-quality, ultra-thick 18/8 stainless steel which is BPA- and Phthalate-free. All components of the cap and bottle are dishwasher safe. Not freezer safe.