Flange fit guide

Why fit matters

A flange that seals comfortably helps you pump without pain. Poor fit can cause rubbing, swelling, or reduced comfort. Pumping should not hurt — stop and seek qualified lactation or medical support if it does.

What's included

Your Embrae One box includes a 24 mm flange as the standard size. We do not claim multiple flange sizes in the box unless separately approved and listed.

How to measure

1. After a feed or pump, when the nipple is at a typical resting size, measure the nipple base diameter in millimetres (not including most of the areola).
2. Use a soft ruler or flange sizing guide printed to scale.
3. Repeat on both sides — sizes can differ.
4. Compare comfort in a short session: the nipple should move freely in the tunnel without scraping the sides.

Signs of correct fit

• Nipple moves freely in the tunnel with little or no areola pulled deep inside.
• Comfortable seal without pinching.
• No lasting ring marks or blanching after the session.

Signs the flange may be too small

• Nipple rubs or scrapes against the tunnel walls.
• Pain, whitening, or compression of the nipple tip.
• Difficulty maintaining a seal despite correct assembly.

Signs the flange may be too large

• Much of the areola is pulled into the tunnel.
• Reduced comfort or a sensation of low effective suction for you.
• Swelling or irritation around the nipple base after use.

What if 24 mm doesn't fit?

Embrae One ships with a 24 mm flange. If 24 mm is uncomfortable after checking assembly, valves, and suction level, contact support. Do not force a painful session. Replacement inserts or accessories are only available when approved and in stock.

Contact support · Replacement parts

Optional measurement helper

Enter your approximate nipple base diameter for general guidance only. This does not diagnose fit.