Adapter is only compatible with MAM 50mm bottles. Adapter is only compatible with Momcozy Portable Bottle Warmer. Bottle warmer adapter comes with a thickened silicone O-ring to ensure safe leak-proof performance. This link is selling only the adapter! Momcozy portable milk warmer is not included. Bottle adapter is made of safe and food-grade materials, BPA-free, hassle-free for mom and baby. Momcozy Portable Bottle Warmer Adapter, specially designed for MAM Baby Bottles with a 50MM neck diameter – the perfect accessory for on-the-go parents! Keep your little one's milk or formula at the ideal temperature, no matter where your adventures take you. Note: This listing is for the Momcozy Portable Bottle Warmer Adapter only and does not include the bottle warmer itself. Make sure to check the compatibility of your Momcozy bottle warmer with this adapter before purchase.