CONTENTS: 4 17mm Flanges, 4 Duckbill Valves, 4 Backflow Protectors, 4 Bottles, and 4 Tubing. All parts are Compatible and Interchangeable with Spectra parts, including bottles. NENESUPPLY COMPATIBLE PUMP PARTS 17mm FLANGE FOR SPECTRA S1 S2 9 PLUS BREASTPUMPS. Made by Nenesupply. Inc. A COMPLETE BREASTMILK COLLECTION KIT Compatible with Spectra S2, S1, and 9 Plus breastpumps. ALL PARTS MADE BY NENESUPPLY. Not Original Spectra S2 Accessories. Not original Spectra Pump Parts and S1 parts. ALL PARTS ARE COMPATIBLE and INTERCHANGEABLE WITH ORIGINAL PARTS that come with your pumps. SAME SUCTION AS ORIGINAL PARTS. Valves, backflow protectors, and flanges form an air-tight seal. The parts can replace Spectra Flanges, Duckbill Valves, Backflow Protectors, Tubings, and Bottles (Wide Mouth). Multiple flange sizes available: 15mm, 17mm, 19mm, 21mm, 24mm, 27mm, 30mm. Backflow protectors fit securely with tubing. The membrane is elastic and flexible and can maintain suction through multiple pumping cycles. It is a closed system and protects your pump. Tubing is longer than original tubing and it is easy to use while pumping. LEAK-PROOF BOTTLES - The bottles come with leak-proof caps and sealing rings. The bottles works with collars and nipples of Nenesupply, Avent and Spectra. The using temperature of the bottles ranges from -20 ~100 degree Celsius. They can be stored in the fridge, and can use bottle warmer to warm up the milk. They can be used as storage bottles and are easy for travel. All parts are BPA free, and Comply with FDA regulations for food contacts. These claims are substantiated with testing reports done by independent labs. Dishwasher safe, and can be cleaned with water steam, boiling water or microwave-steam bags. Flanges have smooth angles so they fit comfortably while pumping. The flange tunnel is at least 32mm, so they are suitable for stretched nipples. Flange