Breastpump Conversion Kit. 4 Sets. Adapt Medela and Ameda Breast Pumps to Fit Avent Bottles. Breastpump Converter. Use With Medela Pump In Style, Freestyle, Swing, Lactina, Symphony, Mini Electric, Harmony. Use with Avent Classic Bottles, Avent Natural PP Bottle, Avent Glass Bottle, Nenesupply Wide-Neck Bottle. Sealing Rings Enclosed