Come and see our amazing products. The outer layer is made of 201 stainless steel and the inner layer of 304 stainless steel. It is double-layered and hollow, which can keep warm and cold, and can also prevent scalding. The material is stable, will not be deformed due to temperature changes, wear-resistant, and easy to be clear. It is a three-piece set, including lid, straw and cup, very convenient to use. Pls confirm with us about the packing info, stock color and exact production time before placing your order