Feature:1. Includeds: With 5 different sizes of flange inserts parts are 13mm, 15mm, 17mm, 19mm, 21mm, 2pcs per size and 2 duckbill valve replacement part.2. Suitable For: Breast pump flange inserts compatible for wearable breast pump, which allow you can pump more milk in the same amount of time.3. Better Fitting: Breast pump flange is better fit the shape of breast, make nipple would not rub or feel squished, effectively prevent nipple swelling.4. Soft Silicone: Breast pump flange inserts are made of silicone material, soft and skin friendly, easy to cleanse, which is safe for mothers to use.5. Regular Replace: It is recommended to replace it every 1 to 2 months. Choosing the right size flange liner can help you pump more comfortably and efficiently.Specification:Item Type: Breast Pump Flange InsertsMaterial: Liquid Silicone.Package List:10 xBreast Pump Flange Inserts2 x Duckbill Valve