The outer fabric of this generously sized cooler bag is made from (RPET) Polyester material. (RPET) is a material made from recycled plastic bottles. The welded inner lining seams prevent leaking, which is great for when your ice melts inside the cooler. All this makes for a more eco-friendly cooler bag that keeps your drinks and food cool and saves you from dealing with a messy puddle of water after a good day out.