Stainless Steel Construction Rugged and rustresistant built with Grade 304 outer wall and Grade 302 inner wall stainless steel and foodgrade polypropylene BPA Free Temperature Control Technology Our unique dualinsulated design keeps your drink cold and fresh for hours BuiltIn Grate A topmounted agitator effectively mixes powders supplements and shakes Locking Cap Our precisionmolded cap with dualtension points keeps the lid secure for added spillresistance BPAFREE