Stainless steel. Built tough. No liners/ coatings. * Insulated lid. Doubles as 8oz drinking cup. Leak-proof stopper. Locks it in. Turns + pours from front/back. * Protective double wall construction. Takes a beating still performs. * Vacuum insulation. Keeps hot/cold 24 hours. * "Anti-Roll" sturdy design. Stays put, won"t roll.