Review on Maxpedition Unisex XBP Expandable Bottle Pouch - XBPGRY: Ultimate Gear Companion for Hydration on-the-go! by Curtis Kincade

Great product if you are carrying smaller water bottles than a 40 ounce hydro. While 40 ounces will do, it won't sit deep in your pocket. The zipper narrows usable space, making the last few inches of the bag unsuitable for a water bottle up to 40 ounces. They have a "tether" that can secure your water bottle, but don't count on your bottle staying in the bag if you're hiking or doing a lot of exercise. The molle straps are very well made and very easy to attach. Behind the bottle compartment is a bonus low-profile pocket that can fit a large smartphone, wallet, or keys, but I wouldn't recommend stashing your smartphone directly behind a metal water bottle. Overall, this is a great product for its niche use cases.