High quality 304 stainless steel 5 layers temperature locking process. The best insulation process keeps the liquid hot for 24 hours and cold for 12 hours. Reusable water bottles replace many disposable plastic water bottles. New screw cap design. The thermos cup adopts the latest silicone sealed vacuum mug design to form an air seal to prevent any leakage. Suitable for all liquids -- can be used as coffee thermos, Coke bottle, juice cup, water bottle, all kinds of drinks. Easy to carry, 15 oz capacity, perfect for carrying around, whether it is outdoor sports, beach, school, picnic, hiking, camping, running, walking, fitness, etc, can easily slide into the bag on both sides of the vehicle-mounted cup holder, a bicycle stand or backpack.