From the Manufacturer NUK replacement spill proof silicone soft spout is especially soft for easy transition to drinking from bottle to cup. Replacement spout fits on the NUK learner cup, active cup, EZ cup, and all NUK bottles to make it easy to mix and match and expand feeding options as your baby grows. Product Description NUK replacement spill proof silicone soft spout is especially soft for easy transition to drinking from bottle to cup. Replacement spout fits on the NUK learner cup, active cup, EZ cup, and all NUK bottles to make it easy to mix and match and expand feeding options as your baby grows.NUK air system minimizes the swallowing of air. Easy to handle and clean. BPA free. Extra soft spout made of silicone. Spill proof for out and about.