The Hydravault FlipStraw Tumbler with Handle 40oz is expertly crafted for exceptional durability and performance. It features a dual-layer design with an inner layer of 304 stainless steel and an outer layer of 201 stainless steel for superior insulation. The handle is made from sturdy polypropylene (PP), while the straw is crafted from durable polyethylene (PE). The lid, made from a combination of acrylonitrile styrene (AS), polypropylene (PP), and silica gel, ensures a secure and comfortable drinking experience.