DESCRIPTION: Please make sure to check the Size Chart [https://cdn.shopify.com/s/files/1/0733/9615/8785/files/555813_325576_480x480.webp?v=1681948832] first before ordering as our flanges have a different design than traditional plastic flanges and sizes from different brands are not directly comparable. BabyMotion Flange transforms pumping into nursing by mimicking a baby's suckling motions. It stimulates nipple and areola, increases pumping efficiency, is soft and comfortable. BPA free. Food Grade. Includes one single so that you can use different sizes for different sides. Compatible with all Medela, Lansinoh, and Hygia pumps. Please check the FAQ section on the BabyMotion Page for how to use with other pumps and email [email protected] for additional questions. 4th Gen improvements over 3rd Gen: softer and more comfortable and discreet design and material.