The Maymom Flange Kit is designed for use with the Philips Avent Comfort Breastpump. This kit includes essential components such as a duckbill valve, tubing, massage pad, suction membrane, top cap, and flange. The flange with the massage pad measures 25 mm, and without the massage pad, it measures 30 mm. This kit is intended for single-side pumping, so if you need to pump both breasts simultaneously, you will need to purchase two units. Note that this kit does not include any bottles and is not an original Philips Avent product. It is made by Maymom and is compatible with Philips Avent Single/Double Comfort Electric Breast Pumps, but not with older models.