To use these belts, simply wrap them around your waist and adjust the fit according to your comfort. They're great for adding a pop of color to your outfits. When it comes to maintenance, you can gently spot - clean them with a mild detergent and a soft cloth. Avoid machine - washing or using harsh chemicals. As for the California Proposition 65 warning, be aware of the potential exposure to certain chemicals. If you have any concerns, it's a good idea to visit www.P65Warnings.ca.gov for more details.