The Camelbak Hot Cap is a double-wall stainless steel vacuum construction Tumbler with copper insulation, which allows beverages to stay cold for 24 hours or hot for at least 8 hours. The construction also prevents condensation on the outside of the bottle. Screw-on lid with twist-open leak proof cap allowing for 360º drinking. Wide mouth opening for easy cleaning and filling. On-trend, durable powder coating. Lifetime guarantee for manufacturing defects with Got Your Bak™. Stainless Steel. 350ml.