Dual wall, 18-8 Stainless Steel with Copper-lined deep draw liner Vacuum insulation provides 9X heat retention Lead-free vacuum seal Leak-proof screw-on lid with visual open/close push button locking closure Lip groove allows for drinking spout to be positioned without even looking Lid comes apart for easy cleaning Powder-coated body with silicone band accent Available in 15 color accent bands Patented