EDIT: after a few months of use, I'm dropping my rating to 3 stars. Honestly this just isn't worth the money at all, and I'd recommend any cheap, adjustable belt with a zipper over this. Even two of those (which is how I often run) is better than this.I *really* wanted to like the FlipBelt. But the water bottles constantly fall out, the phone fits weird, my KEYS fell off of the (very poor-quality) plastic key clip (I'm really grateful I heard them hit the ground). And honestly you just can't adjust this thing...and there are no zippers, it's not waterproof...I don't really know what else to say. The concept is great, especially with the form-fitting bottles, but it doesn't deliver. My runs are so much better with just a cheap belt or two instead of this.The only way I can see this being the belt for you is if you absolutely must have 20+ ounces of water on your waist and don't need to carry phone/keys.Original review:I decided to write a comprehensive review for the FlipBelt, as I agonized and spent tons of time researching and trying other products before pulling the trigger here. Others may find my experience helpful. I have used the belt for three runs now--one 3mi, one 2.5mi, and one 6.5mi, in that order (I don't normally carry water on the shorter ones, and I don't need 11oz on the 6.5, but I carried it just for testing purposes).In my picture you'll see the FlipBelt with bottle on the left, and the other belts I talk about in my review on the right.My final thought (putting first so you don't have to read everything): while it's not perfect, no belt is in my experience. I give this five stars because it allows me to carry more water comfortably on a longer run, which is what's most important in my book and the reason I made this investment in the first place. On its own, without the special water bottle, this belt is not only too expensive, but I find it actually less functional than my other, cheaper, basic belts. If you need to carry many, many things while running, then maybe you'd feel differently.To the review:I have experience using two cheap, adjustable, single-pocket running belts prior to buying the FlipBelt, and I’m going to review here while sort of comparing to my experience(s) with those (see picture for what I’m comparing).Those belts were each 10 bucks and could carry a phone and a key *or* a very small, 6oz water bottle. If I all I need is my phone and a key, I take my favorite cheap belt. If I need to add 6oz water to a run, I add the second belt, and I keep the phone on one hip and the bottle on the other. I can also slip a granola bar or whatever in one of these belts no problem. That system works for me.Neither of those cheap options could do more than that in my experience. I tried a standard (16.9oz) bottle in the one that could even fit that, and no matter where I placed it on my hip or back, the bottle would bounce WAY too much. And I didn’t really have an option for something in between, but I suspect the same would be true if I tried. 6oz is really the max there in my experience.The factors that are important to me that I’ll be talking about: 1) fit, 2) feel, 3) water-holding capacity, 4) other notes. Here goes:1) FitSo, I *don’t* love that the FlipBelt isn’t adjustable. I realize that the design negates that possibility. But my waist size can fluctuate depending on time of year and/or what I’m doing fitness-wise, and I am always messing around with size on my other adjustable belts. Just feels better to me when I can dial in the size whenever I want. With the FlipBelt, if I need another size, I need to buy ANOTHER belt and hope it works.I wear pants with a 36in waist, and I bought the large (32”-35”) here, and I’m glad I did. Fits snugly. Still feels less comfortable than my other belts (a little bulky, a little tight-feeling), but it works.2) FeelI *need* my phone to be in a certain place on one hip, and I *need* my water so be in a certain place on my other hip in order to run comfortably. It’s a delicate balance for me, and it distracts and bothers me if the balance feels off. I appreciate in my other, two-belt system that I can get that perfect every time.The FlipBelt allows that—sort of. I have found so far that I spend the first ½-1 mile in a constant state of adjustment, trying to get the feel just right, moving the bottle and/or phone around the best I can until the balance feels right. It’s not a huge problem, but something I have to dial in as I go.On my first run, the water bottle (which I had to buy separately for another $10) actually fell out of the belt twice within the first mile. I’ve since learned how to get it stuck in there just-so, and it hasn’t happened since, but the fact that it happened at all shows me that the open-entry-point design does leave that possibility of things falling out, where a zipper-design would not.For me, putting the water bottle at the small of the back does NOT work. It was bouncy and unworkable. This could be a function of my waist size vs. the belt size, or just my body type, but it’s something to be aware of. If you and your body can make it work, I can say that this position is the most comfortable feeling while at rest and I kinda dream about it working someday for me. Just doesn’t work while running for me. On my hip, it’s totally fine, snug to my body, and no bounce. For me, that’s remarkable for 11oz of water.And the phone: it’s fine…my case (just a standard plastic/rubbery protective case) creates friction, which is probably a good thing for keeping it from falling out, but it makes it not super easy to get it in and out if I need to do that mid-run. My other cheap belt is easy, I just unzip and pull it out. This takes effort and logistical trickery, which I don’t love while trying to focus on the road, but it’s not a dealbreaker or anything. By the way, it’s an iPhone 7, nothing special. If I had a huge phone, this could be problematic.3) Water-holding capacityThis is why I bought the Flip-Belt, and it is really the ONLY function I truly like and prefer to other belts (but probably the MOST important). I wanted to be able to carry more water and still feel comfortable. I don’t like running with a hydration pack (for me, it’s fine for hiking, but I don’t like running that way), and I need that function in a belt.The bottle design is fantastic for the small of the back (which doesn’t work for me, but that may just be me). It’s fine for the hip. Not perfect (could use more curve for me), but 1000x better than any other water bottle.It slides in and out with ease. The cap opens and closes a little tough, but that’s actually probably good in that it won’t randomly open and leak water all over me. I like the bottle, I like that I can carry 11oz of water and still feel comfortable.4) Other notesThe little key clip thing is necessary in this belt, and I’m glad it has it. Otherwise, my key would go flying into a ditch because of the open entry points.It’s not water-resistant and soaks up moisture. Just a lot of fabric here. My other belts are mostly a utilitarian elastic strap with one pocket, and I have rarely (ever?) felt the need to wash them. This thing already needs a good wash.Cost: it’s an investment. Whatever. In the end, probably worth it if you need to carry more than 6oz water and you have at least one long run per week.Looks: it’s a cool-looking belt. Sleek and stylish.Overall, I'm happy with the purchase, but it was nearly $40 for the belt and water. I would NOT appreciate this belt without the water bottle. You can just get the same or actually better function elsewhere for a fraction of the cost. But the water option was important to me, and this really does do the trick.