You can even put water in the bottles in advance and leave them out at room temperature and use a portable formula container to put premeasured scoops in. Take the guesswork out of it and just fill the bottles by hand. There have also been some concerns raised by pediatricians due to some bottles not getting enough formula added. The price tag on these things are about the same as a larger much more needed baby item, like a car seat-stroller combo.
They hold powdered formula and water, you press a button and it supposedly perfectly mixes up a warm bottle of sustenance. These little doodads are like baby Keurigs but for formula. They're certainly cool and also really expensive and unnecessary. Honestly, I had never heard of a Baby Brezza until I had my youngest, so I'm assuming its a newer invention. You don't have to be fancy and get a Baby Brezza.
Portable baby formula dispenser from Amazon 4.