Using this Hydro Flask cooler cup is a breeze. To use it as a can or bottle cooler, simply place your can or bottle into the flexible collar. The TPU sleeve will hold it securely. If you want to use it as a beverage cup, take the flexible collar off and put it at the bottom of the cup. Your drinks will stay cold for hours thanks to the insulation. When it comes to maintenance, you can wash it with mild soap and water. Avoid using abrasive cleaners as they might damage the stainless - steel surface. Keep it in a dry place when not in use. And remember, this product is BPA - free and Phthalate - free, so it's safe for your drinks.