Healthy Material - The Vacuum double wall was made of high quality grade 304 stainless steel that completely taste-free, rust-proof, leak-proof, The lid was made of food-grade silicone, BPA free, guaranteed high durability. Leakproof Design - The coffee mug lid comes with an airtight silicone seal that prevents the drinks from spilling. Air Vent on the lid allows beverages to flow out smoothly, without gushing or overflowing.The rubber design at the bottom prevents the cup from slipping or tipping. Perfect Capacity - 510 ml capacity, Beautiful and easy to carry,Narrow body design makes it easy to grab and go, also fits most car cup holders and coffee makers. Easy to Carry - Enjoy your coffee easily wherever you go. Suitable for use indoor&outdoor, such as home, parties, travel, school, riding, and office time. Use Notes - The coffee cup buckle can be closed tightly after two "clicks",Hand wash only, the dishwasher is not recommended. cannot put in the microwave..BEST GIFT OF TUMBLER SET: this multi color and 2 sizes tumbler set is designed for everyday use at home, office, outdoor, sports, traveling, camping and driving. Perfect for office workers, drivers, students, teachers, BBQ experts, party favors, sailors, etc. so why not choose ones for your family and friends as a gifts.