Fun fact: the only time Willow® needs an electrical outlet is when it’s charging. Leave a Charger at the office, in your purse, or in different rooms—so you always have one. Bonus: if you have two Chargers, you can charge both pumps at once.

  • Works in any US standard electrical outlet


Free Shipping on Orders Over $70
Free Shipping on Orders Over $70

Find Your Flange Size

with a ruler app on your phone

    Your flange size is based on your nipple measurement in millimeters. Use an app ruler for easy and accurate sizing

    • Download "Ruler 2.0" for iOS or "Millimeter" for Android phones.
    • In iOS app settings, set measurement to “mm”. For Android, select default calibration.
    • Stimulate nipple to perk it up
    • Place phone screen perpendicular to nipple. (Figure 1)
    • Nipple base should line up with the zero points in the corner of app screen (Figure 2)
    • Slide measurement bar on screen to opposite nipple base - that’s your nipple measurement. (Figure 3)
    • Use a flange that’s 2-4 mm larger than your nipple measurement. (Figure 4)
      • Willow Size Guide

        Hold phone
        perpendicular to nipple.

        Willow Size Guide

        Use your finger to slide the ruler line to measure nipple.

        Flange Size Chart 4

        Find the right flange sized based on
        your measurements.

        Flange Size Chart