Using this water bottle carrier bag is a breeze. First, adjust the strap to your preferred length and put it on. Then, place your 40oz tumbler or water bottle in the main part of the bag. You can store your phone, keys, ID cards, and bank cards in the detachable pouch and small pocket respectively. When using it in the car, rest assured that the tumbler fits well in the cup holder. As for maintenance, simply wipe the bag with a damp cloth to keep it clean. Be careful not to use harsh chemicals that could damage the polyester fabric. And remember, the color in the preview images might be a bit different from the real item due to lighting or your monitor.