One of the constant limitations of Apple’s iPhone is its inability to expand storage. When you choose the device, you only have three options: 16GB, 32GB and 64GB—that’s it. If you want more, you either have to take advantage of the numerous cloud services on the market, including Apple’s own iCloud service, or deal with constantly deleting and adding files. Mophie has a slick new accessory that’s capable of doubling (or more) the storage of your iPhone (iPhone 5 or iPhone 5s)—and it acts as a portable battery, too.

Dubbed the Mophie Space Pack, the company’s new accessory is capable of adding 16GB or 32GB—more sizes are being worked on—to your iPhone5/5s, fixing one of the device’s more glaring issues. Not only that, but it combines a 1700mAh battery pack into the case as well, giving the accessory some truly impressive double duty capabilities. During CES, half of TechnoBuffalo’s staff was using Mophie’s Juice Pack products for the iPhone—we would have used the Space Pack had it been available.

We received a short demonstration of the Space Pack’s features—including a full rundown of the iOS app, called Space—and came away impressed by what Mophie has accomplished. The device essentially acts as a portable hard drive (you can even connect it to your computer without your phone attached); anything you can store on a traditional computer hard drive, you can store on the Space Pack, whether it be documents, photos, music or videos. What’s great is that anything stored on the Space Pack can easily be accessed—photos, music and videos play as if they were right on your phone, making for a wonderfully seamless experience.

Dan Kim, Product Category Manager at Mophie, described the Space Pack of an extension to the Juice Pack—now you have the extra phone storage, which will be hugely convenient for power users. The Space app designed by Mophie was easy to navigate, and matched the look and feel of iOS 7; folders can easily be created from within the app, and moving stuff from phone to Space Pack was simple. You can also sync the Space Pack to your phone, so any photos added to your camera roll will automatically go right onto the Space Pack, allowing you to free up that space. Mophie even designed a camera app inside the Space app, which looks almost identical to Apple’s stock camera app, so photos can be taken right onto the Space Pack if you don’t have enough storage on your phone.

The Space app does a great job breaking down the storage used and storage available on the Space Pack, categorizing files by color; it also shows how much battery you have available on the pack itself, allowing you to ration off accordingly. From the brief time we had our hands-on the Space Pack, the experience was very simple to understand, and the app itself was designed well, though we’ll make final judgements once we get the chance to use the final product. It’s a wonder no other company has thought to combine the usefulness of an expandable battery with expandable storage for the iPhone. The only drawback? You can’t store iOS apps to the Space Pack’s internal storage. That means it’s best for folks who find that media takes up the lion’s share of their iPhone storage.

From what we saw, the Space Pack will almost certainly be a hit, though you’ll unfortunately have to pay quite a bit—$150 for 16GB and $180 for 32GB—if you want to take advantage of Mophie’s creation. The fact that it combines extra storage and battery will no doubt attract a lot of users, however—we can’t wait to try it out later this month.