Flange Inserts 13/15/17/19/21mm 10PC, Compatible with Momcozy S12 Pro/S9 Pro/S12/S9 Wearable Breast Pump Cup: Our 10PC set of flange inserts is designed to provide a comfortable and secure fit for wearable breast pump cups. With sizes ranging from 13mm to 21mm, you can choose the insert that best suits your individual needs. Enhanced Comfort and Efficiency: These flange inserts help improve comfort during pumping and support efficient milk expression. A proper fit can reduce discomfort and enhance overall pumping performance. Easy to Use: Installing these inserts is simple. Just select the desired size and place it inside your breast pump cup for a secure and customized fit. Durable and Safe Materials: Made from high-quality materials, these flange inserts are safe for use and built to last. They are free from harmful substances and designed for repeated use without loss of performance. Compatible with Various Models: These flange inserts are compatible with a range of wearable breast pump cups, offering versatility and convenience for different pumping setups.