To use these belts, simply wrap them around your waist and fasten the buckle. They are stretchy, so they can fit a range of waist sizes comfortably. When it comes to maintenance, avoid exposing them to harsh chemicals or excessive heat. You can gently clean them with a soft, damp cloth. Also, keep in mind the California Proposition 65 Warning. If you have any concerns about the chemicals in the product, visit the provided website for more details.