Using this water bottle carrier bag is a breeze. First, slide your 40oz tumbler or water bottle into the main part of the bag. You can adjust the strap to a length that suits you best, anywhere from 24 to 48 inches, and wear it comfortably. Put your phone, keys, ID cards, and bank cards in the detachable pouch or the small pocket. The zipper on the small pocket helps keep your stuff from falling out. When it comes to the car, you can place the tumbler with the carrier bag in the cup holder without any trouble. As for maintenance, simply wipe the bag with a damp cloth if it gets dirty. Since it's made of polyester, it's durable but avoid harsh chemicals. Also, remember that the color in the preview images might be a bit different from the real thing because of lighting during the photoshoot or your monitor settings.