Our 30 oz. double walled stainless steel tumbler is constructed of 18/8-304 food grade inner and a 201 stainless outer grade material. The recessed contour design is perfect for most cup holders in cars, boat and golf carts. This tumbler will keep the temperature of your favorite beverage longer than your average mug. Perfect for people on the go, for the home and office, for any outdoor activities and long distance travel. Comes with a clear, spill proof lid with thumb slide