Product Description Maymom provides great alternatives to speCtra pump parts for spectra S2 accessories and spectra S1 accessories. This single sided kit contains 1 flange 1 duckbill valve 1 tube 1 backflow protector Why selling only ONE-sided kit? Not every mother was born with two nipples of the same size. For pumping comfort, a mother can choose different sized flange kit for her respective nipple. Why chooses Maymom This pump kit is made and improved by Maymom to fit spectra S1/S2/9+ and Spectra M pump. It is well-known that using correct size of flange in breastmilk pumping is crucial in achieving pumping comfort and efficiency. Since every mother was created differently, one or two sizes can't fit all. That's why Maymom develops more than 12 sizes of flanges. Maymom is specialized in developing pump parts that can work with many name brand pumps on the market. Maymom cares for each mom! Maymom MyFit Pump Kit for Spectra Breast Pumps Contents: 1 Flange, 1 Duckbill Valve, 1 Backflow Protector, 1 Tube Hygienic replacement kit for spectra S2 and spectra S1 pumpsSpare parts for traveling and less frequent cleaningVarious sizes of Flanges to choose for pumping comfortFDA compliance for food contact.Made from BPA free and DEHP free materialsSame function as OEM parts Great replacement kit for Spectra pump parts Interchangeable with Spectra S2, S1, 9 Plus Pump parts Read more Product Description Available In Multiple Flange Sizes Research shows that flange size does matter for pumping comfort and efficiency.Maymom designs a wide range of flange sizes - 13 to 32 mm in small increments to meet every mother's pumping needs. We also provide inserts to complement some mothers' special needs.Follow the selection guideline of this listing to pick your optimal flange or consult a lactation consultant for help. . Backflow Protector No milk backflow into your pumpInterchangeable with OEM upper case, lower case, diaphragm, tubing and OEM flangeTighter construction for better seal during pumping Longer and User Friendly Tubing Length: 42 inches - Longer than OEMQuality: BPA and DEHP free silicone tube - Safe for mothers and babiesEfficiency: Easy to plug in, remove and storeDurability: For long-term use Identical Valve Design Same shape and function as OEM valveSturdier base for removal and installationThinner and wider opening for smooth milkflow and better seal and suctionNo more dropping valve in the milk during pumping Read more Frequently Asked Questions- Q: Can I use a handsfree bra with this kit? A: Yes and no. Being the one-piece design, the breastshield is only compatible with SOME handsfree bra on the market, like Simplewishes and Simplicities. However, Maymom just releases SEPARABLE two-piece flanges to fit almost all pumping bras on the market. Click the key word "Maymom MyFit" on Amazon to get more details. Q: Why is there no suction or low suction power? A: 1. Please check if you have installed the duckbill valve or valve/membrane. Many new mothers forget to do so. 2. Make sure the air path in the flange is not blocked. 3. Check to see if the diaphragm inside the backflow protector can move freely. 4. If you can't solve the issue, contact the seller with a photo of your setup for help. Q: Why does Maymom 28mm flange look bigger than OEM 28mm? A: Many mothers told Maymom that they experience pains from the nipple hitting the back of the spectra OEM 28 mm flange. Maymom designs her 28mm flange to be longer and roomier so no more nipple hitting the back of the flange and there is more room for the nipple to move. However, Maymom still keeps the Internal Diameter at the entry point of the nipple tunnel same as the OEM one; that is, 28 mm. Q: How to avoid breaking the backflow protector during setup with the flange? A: Turn to insert the backflow protector into and off from the flange with care. DO NOT push in or rock straight in and out with force. It will break. Q: Where can I find the size marking on the flange? A: It is marked at the end of the nipple tunnel. Maymom shield size refers to the INTERNAL DIAMETER (ID) at the ENTRY point of the nipple tunnel. Q: How do I choose the flange sizes? A: For optimal comfort, we suggest you start to try a flange size that is 2-4mm larger than your nipple diameter. Since your nipples will enlarge after pumping, measure the diameter of your nipples AFTER a pumping session. Do not include the areola. However, the best fit will never be discovered until you really try it out. Q: Why did the flanges break after only a few uses? A: Maymom's flanges are made heavy-duty and durable. However, shipping conditions can be harsh. Many stresses imposed on the product during shipping do not show up until the product is used or sterilized a few times. If you encounter this situation, contact the seller for a free replacement. Collection Bottle with One-Piece Cap Duckbill Valve Wide-Mouth Flange Tubing for Spectra Pump Parts for Spectra Storage Bag Adapter for Spectra Number 6 Pieces 2 Pieces 2 Pieces 2 Sets 2 Sets 2 Sets Work With Spectra Pump Parts ✓ ✓ ✓ ✓ ✓ ✓