Using this water bottle carrier bag is a breeze. First, adjust the strap to your preferred length. It can be detached if you don't want to use it. Put your 40oz tumbler or water bottle in the main part of the bag. For your personal items like phone, keys, ID cards, and bank cards, use the detachable pouch and the small pocket with a zipper. When you're in the car, you can place the tumbler (still in the bag) in the car cup holder. As for maintenance, simply wipe the bag with a damp cloth when it gets dirty. Just remember that the colors in the preview images might not exactly match the real item because of lighting during the photoshoot or your monitor. Keep this in mind and enjoy your on - the - go lifestyle with this handy carrier bag.