The Iron Flask 20 oz Nomad Tumbler is the perfect travel partner for the nomad in all of us. Every tumbler cup is made with the highest-quality stainless steel and a powder-coated finish to hang tough with even the most accident-prone among us. Double-walled insulation means your drink of choice stays cold for 16 hours or hot for 4 hours, and, to make life even easier on the go, each insulated tumbler comes with a leak-proof flip lid for hot drinks and a splash-proof straw lid with two straws for everything else.