
Each side is controlled separately, and you’ll see a timer in the app to show your overall pumping time for each pump (but not how long you spent in each mode). You can manually switch modes on the top of the Willow and within the app, and change around the intensity, too, to find the ideal setting. The Willow Go will start out in stimulation mode for two minutes before switching to expression, to try to replicate how a baby starts feeding and activate let down. Both have a few levels of suction and rhythm to choose from in the app. The Willow Go has two pumping modes: a stimulation mode and an expression mode. You always turn the pump on manually to start a session, but you'll need the Willow Go app handy to see see what mode or level you're using (you can sense a difference in these, and the Willow always starts on the lowest level) and how long you've been pumping.
MEDELA PUMP IN STYLE PLUS
There are a couple of minimal physical controls on the Willow itself: a power button, a mode button, and a plus and minus button to change the suction level. You use that opening to pour out milk at the end of your session, and you can easily splash milk out of it if you were to bend too much. You won't want to do any tasks that require major bending (so skip loading the dishwasher bottom rack), because the Willow Go has an opening at the top. Once I was pumping, I found it pretty comfortable to wear, and I could pump while moving around my house, typing at my desk, or even washing dishes. The app guided me through fitting the parts together, properly placing it within my pumping bra, and starting my pump session.

But the Willow Go comes with a sizer and a guide for which of the included two flanges and inserts to use to get the perfect fit, no advance work required.

Many brands ask you to know your size to order the right flange set, and you don’t want to get this wrong, as opened breast pumps usually can’t be returned. If it's too small, the flange doesn't catch all the milk too big, and the pump will suck in the outer parts of your areola. Any lactation consultant will tell you that a properly fitted breast pump is key to getting the most milk out of a session, and it makes it more comfortable to use.

Before you ask, a flange is what some people call the breast shield-the plastic piece that fits over your nipple. The biggest upside about the Willow Go compared to other wearable breast pumps is that you don’t have to know your exact flange size in advance.
