Made of plastic, otherwise known as cellulose acetate, or zyl, the frame can be easily adjusted for a perfect fit with your prescription lenses. Your frame purchase includes free standard shipping charges, and manufacturer packaging. You can add doctor verified prescription lenses, add custom polarized lenses, and many other lens options if you desire them. Like all cK Calvin Klein products, the cK Calvin Klein CK23521 provides the sophisticated and classic look that we all need.