Medela Freestyle™ Hands-Free Membranes are extra membranes for your Medela Freestyle™ Hands-Free Breast Pump Set. They are one of the three parts of our easy-to-assemble Medela Freestyle™ Hands-Free Collection Cups. These extra membranes are useful if you want to have a spare set while the other is being washed. Membranes occasionally gets damaged while washing, causing breast pump to leak. Be sure to examine your pump parts regularly, if you notice damage or extensive wear replace immediately. Medela recommends replacing your membranes every 3 – 6 months, depending on your pumping frequency. COMPATIBILITY: Works only with the Medela Hands-free Collection Cups REPLACE REGULARLY: Medela recommends replacing your membranes every 3-6 months, depending on your pumping frequency MADE WITHOUT BPA: Hands-free Collection Cups Membranes are made of 100% food grade silicone WHAT'S INCLUDED: Each pack includes two (2) Hands-free Collection Cups silicone membranesMedela Freestyle™ Hands-Free Membranes are extra membranes for your Medela Freestyle™ Hands-Free Breast Pump Set. They are one of the three parts of our easy-to-assemble Medela Freestyle™ Hands-Free Collection Cups. These extra membranes are useful if you want to have a spare set while the other is being washed. Membranes occasionally gets damaged while washing, causing breast pump to leak. Be sure to examine your pump parts regularly, if you notice damage or extensive wear replace immediately. Medela recommends replacing your membranes every 3 – 6 months, depending on your pumping frequency. COMPATIBILITY: Works only with the Medela Hands-free Collection Cups REPLACE REGULARLY: Medela recommends replacing your membranes every 3-6 months, depending on your pumping frequency MADE WITHOUT BPA: Hands-free Collection Cups Membranes are made of 100% food grade silicone WHAT'S INCLUDED: Each pack includes two (2) Hands-free Collection Cups silicone membranes