When it comes to wearables, fit really matters — and fit starts with your flange. The Perfect Fit Bundle makes it easy to take your nipple measurements, experiment with sizing inserts, access expert-backed education, and connect with a Sizing Specialist for personalized guidance.

• A set of four inserts (sizes 13mm, 15mm, 17mm, and 19mm) that fit inside our 24mm flange to help create a more snug fit
• Access to expert-led videos for help with measuring, choosing your insert size, and more
• Access to a 1:1 virtual session with a Willow Sizing Specialist

• Measure your nipples once your bundle arrives. Check out our videos for tips!
• Add 0-2mm (if you’re pumping with Willow 3.0) or 1-3mm (if you’re pumping with Willow Go) to find your size. Our Digital Sizing Guide has step-by-step directions — and if you already have your pump, you can use the Nipple Sizing Tool that came in your kit.
• If your flange still doesn’t feel comfortable, experiment with the other inserts. (Also, make sure you’re wearing a snug, stretchy pumping bra!)
• Book a session with a Sizing Specialist if you need additional support.