Made with food-grade, corrosion-resistant 304 stainless steel Keeps beverages hot for up to 6 hours, or cold for up to 12 hours Includes removable stainless steel strainer Designed by Native American artists Hand wash only This tumbler is crafted from 304 corrosion-resistant stainless steel, featuring a double-walled and vacuum insulated construction to keep beverages hot up to 6 hours or cold up to 12 hours. The Raven design was created by Bella Bella artist Ben Houstie, a Native American artisan from the Pacific Northwest region.