It's been three years since a smart breast pump stole the show at CES 2017. Since then, Willow has been doing what any tech company would do after it has its first hit: iterate, iterate, iterate. Over the past few years, Willow has made its wearable breast pump easier to operate, and it's also added an optional reusable container for moms who don't like the idea of trashing disposable milk bags.

This year, at CES 2020, Willow is unveiling its third-generation pump (and allowing its space to double as a breastfeeding room for nursing mothers attending the show). Though the device looks similar to last year's model, the company is touting some under-the-hood improvements that promise better comfort and a higher milk yield. Specifically, the company claims that moms can expect around 20 percent more milk, on average, per session. (That's based on focus groups with "experienced" users who pumped at least 20 times in testing.)

As for comfort, the company has added new suction levels, a slower, gentler pumping rhythm, a "sensitivity" setting and a feature that adjusts the suction settings based on the user's preferences.

Of course, the Willow wouldn't be the Willow without some signature hardware features. Like both of its predecessors, it takes the form of two wearable, battery-operated cups -- one of the device's chief selling points has been that moms don't need to sit tethered to a wall outlet while breastfeeding. The pump sends milk straight into a receptacle, whether that be the standard disposable bag or the reusable container, sold separately.

The device is also designed to be quiet -- an area where Willow makes progress with each successive generation. Lastly, Willow's shtick is that it promises a design so leakproof you can even do yoga poses while wearing it, though you'll have to take someone else's word for it -- our staff has yet to test that claim.

On the software side, the companion app is being updated with personalized pumping tips, onboarding help for new users and what Willow claims is a faster, easier pairing process. As ever, the app tracks volume over time, so women can see how much milk they've produced in various pumping sessions.

Willow Generation 3 will be available sometime this spring for $499.99, the same price at which the last-gen model launched. Like its predecessor, it will come with two pumps and 24 milk bags. It will be available in three sizes: a new 21mm, along with the current 24mm and 27mm sizes. The second-generation model will still be sold, also for $499.99 but with a container included. That, too, will be available in the smaller 21mm size, though don't expect the older device to work with the new app; those software features are reserved for Generation 3.