How to choose your size?
Choose your Flange size
Stimulate your nipple until it perks up and measure the diameter of your nipple in mm, from base to base. You can measure it with any ruler, an online ruler, or our printable sizing tool.
We recommend measuring your nipple before pumping or breastfeeding, as it should be at rest and not enlarged by suction. Be sure to measure both nipples, as they may differ in size.
| Measurement | Flange size |
| up to 11mm | 15mm |
| from 11mm to 14mm | 18mm |
| from 14mm to 17mm | 21mm |
| from 17mm to 20mm | 24mm |
| from 20mm to 25mm | 27mm |
If you need two different sizes for each breast:
• If you are buying a double Perifit Pump, add two single Perifit Pumps of different sizes to the cart and apply the discount code MIXMATCHDOUBLE.
• You can also opt to buy an additional flange.
Tips for detecting the wrong size:
• Your nipple rubs against the sides of the tunnel and creates discomfort or irritation: your flange is probably too small
• Excess areola tissue is sucked into the tunnel: your flange is probably too large
• Is there any visible redness?
• Is your nipple or areola turning white?
• Do you feel that not all your milk has been pumped after expression? If you find yourself in one of these situations, we recommend that you try a different size flange. Do not hesitate to contact us to help accompany you with your choice!