HOW TO SOLVE THE LIPS POPS BACK UP? As we all know, the air with boiling water expands in the sealed bottle. The air inside will pop lip back up after you close the tumbler lip quickly. Maybe the spilling hot coffee will be all over you. How to solve it? 1.Close the lip after two minutes when fill in hot drinks. 2.Close the lip but open the hole in the middle. Close the middle hole after two minutes Cup holder friendly Tumblers Cup Holder Friendly. They'll fit in almost any cup holder on cars, boats, chairs, etc. Perfect lightweight 30oz capacity gently also fits easily in your hand. Keep your water colder longer Double-wall vacuum bottle keeps your drinks like coffee, wine, tea, water, juice, wine, ice cream hot up to 6 hours and cold up to 24 hours, when you go on an outdoor or your day gets busy. Easy to clean Wide mouth allows cup brush easy to the access mug inside, eliminating hard to reach spots. The interior is electropolished, which is rustproof will never leave a metal taste or rust. Read more No spilling Also the lid is also spill proof. Only keep the lip seal it, though you drop it on the floor, even knock this cup over,never spill, keep your kids, pets, even work laptops and documents on the desk safety. Wonderful gift for lover We offer tumbler set, which is a good gift choice for your friends, family members and coworkers. Every time she drinks, the cups will remind her that you love her the most! Dishwasher safe The tumblers are used to clean by the dishwasher. Read more What Comes to You -4 × 30OZ Stainless Steel Tumbler with ABS Lid -4 × Stainless Steel Curved Straw -4 × Straw Brushes -2 × Straw Brush Read more