Using this Hydro Flask cooler cup is a breeze. First, you can simply place your 12-ounce slim can or pour your favorite beverage into the cup. If you're using a can, put the flexible collar around it to lock in the cold. For a regular drink, use the collar at the bottom to keep the cup stable. You can take it with you in your car as it fits most cupholders. When it comes to maintenance, since it's dishwasher safe, you can just pop it in the dishwasher for an easy clean. However, to keep it looking its best, avoid using abrasive cleaners. Also, make sure to dry it thoroughly after washing to prevent any rusting. This cup is BPA-free and toxin-free, so you don't have to worry about any harmful substances leaching into your drink.