Using this Hydro Flask tumbler is easy. First, open the Closeable Press - In Lid by sliding it open. You can pour your hot or cold drink into the tumbler. If you're using a reusable straw, there's enough space to insert it through the open lid. For sipping, just take a drink directly or use the straw. When not in use, slide the lid shut to keep the temperature and prevent spills. As for maintenance, you can safely put it in the dishwasher thanks to the Color Last™ powder coat. This will also help keep it slip - free and looking colorful. Remember, since it's made of 18/8 pro - grade stainless steel, it's durable, but try not to drop it hard as it could still get dented. Also, because it's BPA - Free and Toxin - Free, you don't have to worry about any harmful substances leaching into your drink.