Please note that the following sizes are included for the eufy Breast Pump S1 Pro, S1, and E10 models. 17/19/21mm inserts are compatible with the 24mm flange. 

• 17mm
• 19mm
• 21mm
• 24mm

Additionally, you also have the option to purchase a 27mm flange on the eufy official website.

If you have any further questions regarding the eufy Breast Pump, please don't hesitate to reach out to us for assistance.