Thermos vacuum insulation technology locks in temperature to preserve flavor and freshness to keep beverages hot for 6 hours Durable 18/8 stainless steel interior and exterior withstand the demands of everyday use Simple stainless steel brewing mechanism brews without electricity so you can make coffee anywhere in 3 simple steps 1. Add ground coffee 2. Fill with hot water, then cover 3. Wait 4 minutes, press plunger and enjoy Body stays cool to the touch with hot liquids