Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: How leak proof is this? Can it handle jostling inside a backpack? I am considering this for hiking.
Document: Another thing I love about it is that it's leak-proof. When sitting in class, my backpack always lies flat on the floor and the liquid never leaks, even when the tumbler is full! Cleaning is also a breeze. I like how the opening is wide so I can clean the inside without using a brush. The purple color is absolutely gorgeous. I've received so many compliments from friends and strangers about how beautiful this tumbler is.
SealsTwo soft seals in mechanism ensure no leaks. However I'm not sure how long these will last. Thermos has not replied to my enquiry about replacement seals. Tumbler will still be useable, but not leak proof without the soft seals.2. Where to drink fromTwo slit openings on the inside depressed section allow liquid out. Because there is no handle, there is no tactile reference point when the tumbler is picked up as to where to drink from. That may be why a reviewer had problems with spillage.
I am a Chicago commuter and a maturing coffee addict. Since our public trans system can be extremely crowded, I needed the following characteristics:~Easy to hold (1 arm is usually propping myself up) & aesthetically pleasing (my girly side)~Leak/spill proof~Opens/closes with one motion~Stainless steel~Retains heat/cold temperature~ALL components can be cleanedI paid $23. Not bad considering it held up to all my requirements.
This mug is truly leak proof! I haven&#8217;t tried anything cold in the mug yet however, all the hot beverages have stayed hot for several hours. I toss it in my backpack and don&#8217;t worry about it leaking on my things.Well built little mug that I would recommend!
This product does what it says it does. I fill it up at 9am and my coffee is still nice and hot at 1pm for lunch. Easy to take apart for cleaning, although that is my least favorite task. It is truly leak proof. I fill it up and seal the lid and toss it in my backpack with no problems. Elegant finish and good construction.
I was looking for a thermos type mug that I can transport in my briefcase that didn't have a handle and kept my coffee hot for hours. My drinks stay hot for a very long time..so much so that I can brew my coffee the previous night at 10pm and it will be perfect the next morning until the afternoon.It is pretty leak proof however if you use a french press and course cut coffee beans to brew your coffee, the bits could get trapped under the sealing flap causing a leak.
It went from 2pm to 11pm and there was STILL ice in it! I'm so amazed at how well it works but I also did try the leak test... I flipped it upsidedown and shook it as if it was laying around in a backpack. Drops of water still came out but for the most part it was pretty leak proof. The only thing I don't like about it so far is how squeaky the lid is when you are screwing it on.
This is the best mug I've ever bought. Yes, it was expensive. It is tall but still fits under my Keurig if I take out the spill tray on the bottom. I only buy mugs if they are leak-proof enough to throw in a bag or backpack on my way to school or work. This mug is totally leakproof enough for that. The design is sturdy. It keeps my drinks ridiculously hot, which is a slight problem for me since I can't drink things boiling hot.
Having to completely disassemble the lid to clean it properly.3. From constantly removing the seals for cleaning the seals begin to stretch.Overall the mug is fantastic for its superior ability to keeps drinks warm and leak and spill proof. Maybe an indentation in the lid or some sort of marking to reference the drinking points would be greatly appreciated. If not I'd reccommend the mug with the handle.
Also, it's great in the summer when my car is over a hundred degrees. My ice water refuses to heat up and I have a nice, cool drink for the whole commute home.The seal on the inside of the lid is totally leak-proof too. When the lid is sealed, you can carry this mug upside down with no problems.
Answer: Completely leak proof! Solid design that will handle all terrain and keep your drink warm or cold for hours. The button to open and close seal is solid too, so accidental opening is practically non existent.