Koi 4 Pros:Its incredibly hard to find a portable charger that works with the Surface Pro 7, so after doing some research I learned about the ZMI. Not only does it work with my Surface, but it also works with any of my other devices. The design is nice, and it also works as a portable hard drive. You’re not going to be storing mountains of data on it, but its a cool design feature that could save you in a pinch.Cons:Its extremely heavy, but the fact that its so hard finding a portable charger that works on my Surface makes the weight not a big deal. It takes an EXTREMELY long time to charge its own battery, so you have to plan ahead. But once you get past those two things, its well worth it if you’re buying it to charge your Surface Pro.