RELIABLE MATERIAL: Our baby bottle caps are made of BPA-free PP material, safe and reliable, not easy to break or deform, lightweight and easy to use on the go. LEAK-PROOF DESIGN: The baby bottle caps are capped with a sealing ring on the inside to ensure excellent sealing performance, preventing breastmilk or formula from leaking even when inverted for long periods of time and strongly shaken. AIR TRAVEL FRIENDLY: Ideal for air travel to counteract the effects of cabin pressure. Travel baby bottle caps keep air and dust out, keeping breastmilk and formula fresher for longer period and easy to store. Fits a variety of PPSU/PP/Glass Wide-Neck Baby Bottles for easy travel. EASY TO CLEAN: The reusable baby bottle travel cap is dishwasher safe (top holder), suitable for electric sterilizers, microwave sterilizers or boiling water. BPA free for safety reasons. COMPATIBILITY: These travel baby bottle caps are specifically designed for pigeon wide neck bottles and can also be used on Evenflo, Lansinoh, and Motif brands of wide bore bottles. Please note that our products are not sponsored or endorsed by or associated with the brands they fit, including Pigeon, Evenflo, Lansinoh, and Motif