Quick answer

Start with the CustomFit 2-Piece Hard Flange in 17mm, 19mm, or 21mm and adjust until your nipple moves freely without rubbing the tunnel. If you use the GLO Wearable Breast Pump, keep a spare GLO Collection Cup on hand so a lost or damaged cup never interrupts a session. Both parts are inexpensive, replaceable, and designed to work with the Ameda system you already own.

How do I know which CustomFit flange size to start with?

The CustomFit system offers 17mm, 19mm, and 21mm, which covers many but not all pumpers. A practical starting point is to measure your nipple diameter at the base before pumping and add roughly 2–4mm for comfort, then round to the nearest available size. If you are between sizes, begin with the larger one and size down only if you see persistent rubbing or a ring of milk left in the tunnel after a session. Because the two-piece design pairs a universal base with interchangeable flange sizes, you can swap just the flange instead of replacing the whole setup.

What does a good flange fit actually feel like?

A correct fit means your nipple is centered, moves freely in the tunnel, and does not touch the sides during the pump cycle. You should not feel pinching at the base, and you should not see your areola pulled deep into the tunnel. Some gentle movement of the areola into the flange is normal; persistent pain, blanching, or a visible crease line is not. If any of those happen, stop and reassess your size before continuing the session.

When should I replace a CustomFit flange?

Replace the flange when you notice cloudiness, scratches, or a stretched or loose fit on the base. Small scratches can harbor residue and reduce the seal, which shows up as weaker suction or milk backing up. Because the CustomFit flange is a two-piece system, you can replace only the worn flange and keep using the same base, which is usually the cheaper path. If you pump several times a day, inspect the flange weekly and replace at the first sign of wear.

What is the GLO Collection Cup for?

The GLO Collection Cup is the replacement cup designed exclusively for the GLO Wearable Breast Pump. It is the part that collects expressed milk, so a lost, cracked, or cloudy cup can sideline your pump until a replacement arrives. Keeping an extra cup on hand means you can rotate one while the other is drying or being sanitized, and it keeps your pumping schedule from depending on a single part. It is made from BPA-free materials and fits securely into the pump.

Can I use CustomFit flanges with the GLO pump?

The CustomFit flanges are designed to work with Ameda HygieniKit milk collection systems and Ameda breast pumps, but the GLO Wearable Breast Pump uses its own collection cup rather than a separate flange and bottle setup. If you are not sure which parts your pump takes, check the pump model name before ordering. Mixing parts across pump families is the most common reason a flange or cup will not seat correctly.

How should I clean and store these parts?

Rinse both the flange and the collection cup in cool water right after pumping, then wash in warm soapy water and air-dry on a clean rack. Avoid abrasive brushes on the flange tunnel, since scratches affect the seal. Store dry parts loosely assembled so air can circulate; a sealed bag traps moisture and encourages cloudiness. If your pump parts stay damp between sessions, a second set is often more useful than a longer cleaning routine.

Quick fit and parts checklist

Measure before you buy

Check your nipple diameter at the base and compare it with the 17mm, 19mm, and 21mm CustomFit sizes. When in doubt, start with the larger size and size down only if you see rubbing.

Watch for fit warning signs

Pinching, blanching, or a crease line at the base means the flange is too small; areola pulled deep into the tunnel means it is too large. Adjust the size before continuing the session.

Keep a spare of the part you use most

A second GLO Collection Cup or a spare CustomFit flange means a lost, damaged, or damp part does not stop your pump schedule. Rotate parts so one can dry while you use the other.

Product facts

  • CustomFit™ 2-Piece Hard Flanges Non-Sterile: The Ameda CustomFit 2-Piece Hard Flanges come in smaller, precise sizes: 17mm, 19mm, and 21mm, and pair a universal base with interchangeable flange sizes. You can fine-tune fit and keep a secure seal without buying a whole new pump setup, and you only replace the flange that wears out.
  • Ameda GLO Collection Cup: The Ameda GLO Collection Cup is a replacement part designed exclusively for the GLO Wearable Breast Pump, made from BPA-free materials. A spare cup keeps your pumping schedule uninterrupted if a cup is lost, damaged, or still drying.
  • Ameda Igloo Reusable Cooling Element: The Ameda Igloo Reusable Cooling Element is part of the Ameda Cool'N Carry Storage System and can also be used on its own for cooling needs. If you pump away from home, a reusable cooling element helps you store milk safely without relying on a fridge.