These 26oz bottles are tough enough to go anywhere you can go and then some. Designed with Double Wall Stainless Steel enclosing a Copper Vacuum Insert to increase their insulation, these rugged wonders were built to keep your super hero juice cold for 24 hours and hot for up to 12 hours. They have an insulated threaded cap, can withstand 3rdNut style bumps, falls and abuse without cracking or spilling. Keep hydrated and save the planet by getting rid of those one use bottles…very 3rdNut. Enough said.