18/8 stainless steel double wall construction, it’s also made with BPA-free materials, handle can fold, lid as a cup, this insulated thermos is an ideal bottle to throw into your truck, work bag or travel with it, keeps liquids hot or cold drinks cool for up to 24 hours, 1.5QT-47oz besides also have 34 oz reference HKH256, and 64 oz is available email please.