These Extra thick 2 mm Rustproof Aluminum chairs are light yet very durable and stackable Dura Wood (Synthetic Wood) has been through rigorous laboratory testing including 3000 hours of direct UV exposure They are manufactured for Commercial use in high traffic areas Used at restaurants, resorts, hotels, weddings Ideal for indoor and outdoor use, this is an excellent choice for your home or your business Material: Frame is extra thick 2 mm Aluminum Seat & Back: Dura Wood (Synthetic Wood) Quick Shipping Covered by an industry-leading 3-year residential and 1-year commercial warranty