GOOD INSULATION: The 20 Oz stainless steel slim tumbler is with Double-Wall vacuum technology to keep drinks hot for over 5 hours and keep cold for 9 hours. Use it to enjoy a warm drink even in winter. This unique tumbler makes companion for any drinks. USE INDOOR & OUTDOOR: Our skinny tumbler is suitable for any indoor or outdoor places. Fit for enjoying drinks at home, on the beach, by the lake, at the pool, in the office, at the party, during RV tours, cabin trip, camping, hiking, picnic and so on. Enjoy the time of drinking without other concerns.