Review on 🍶 Thermos 3410USP 'Add-a-cup' 35 OZ. Beverage Bottle - Versatile & Colorful! by Jennifer Wurz

First of all none of the sellers I tried to contact about this item could give me complete information. I read other reviews (about the same product from other sellers). People were concerned about its durability and fragility. The inner vacuum bottle of the item is actually made of thin glass which is easy to break. And yet (from various sellers, including the one I bought from) it comes somehow unlovingly packaged. It's just in the shipping box with no extra bubble wrap or anything like that. Sometimes it even breaks (see product reviews from other sellers). Therefore, please check the seller's return/refund/replacement policy before purchasing. And that extra packaging is really important considering how the product is made. The quality of the outer plastic cover is ok (as far as you can tell today with things made in China). Luckily for me, the bottom of the case unscrews (none of the sellers could tell me that. They just don't know what they're selling. One of them even told me that "according to the manufacturer, the bottom cannot be opened" - what is wrong).So if you happen to find a spare glass inner vacuum bottle, you can easily replace it by yourself.But the inner vacuum bottle is not fixed.It has a kind of rubber "cap" at the bottom to protect the protect the delicate 'tip' (which is created when creating a vacuum). The 'neck' of the vacuum bottle touches the liner at the top of the outer shell (and the liner doesn't fit into the 'neck' as expected). And all. The inner glass so it's not fixed by anything.It was very shaky inside.That's why it can easily break even if the bottle falls on its side.To secure the vacuum glass bottle inside, I cut out some styrofoam pieces and put them in between the glass and the outside plastic plugged in. Now the inner glass is held securely. Another thing is the insert at the top of the bottle. Between the insulating glass bottle and the hole in the outer shell. The quality here is below my expectations (and there was nothing I could do to improve it). The liner does not fit the hole like a glove. The diameters don't seem to match. It also looks like the cork might not insulate enough when screwed in. The tip of the cork does not go deep enough into the glass bottle. It looks like it's just covering the hole. And this can be the weakest point where you lose heat. I'm only interested in hot tea/coffee and tested a bottle of hot tap water (very hot, you can't put your hand in for more than 2-3 seconds without getting burned). Basically, it could be something like a manufacturer's guide stating that it can keep warm for up to 8 hours and cold for up to 12 hours. Because after about 10 hours, the water in the bottle was far from the original temperature. But after 4.5 hours the temperature seemed high enough to be described as "relatively hot". Again, I didn't test it with cold water (because I don't particularly care). But make sure you DO NOT put ice in it. The instruction manual says it's a big no-no, and other reviewers agree. One reason could be that the glass is very thin and if you throw an ice cube in it, it breaks easily. I also looked at 'twist and cork'. I personally wouldn't use it. It won't help avoid the mess. And its shape (big gap in the threads) doesn't really guarantee me that the cork sufficiently insulates the "mouth" of the inner glass to avoid heat loss. Leaks have not yet occurred, judging by the build quality (see above). about the cork and the insert) I probably expected (as did the other reviewers). Especially if you leave the bottle on the side for a while. The 2 plastic cups used as lids are actually good for those who don't want to carry around an extra cup/glass for someone else. The cups are about 7 ounces I think. In general I like the product (especially from this seller at a lower price). UPDATE: After these years of use, we finally noticed small leaks on the bottom cap. and the bottleneck. When we opened it, we found that these styrofoam inserts had to be replaced. And the reason for the leak was that the lower piece of rubber hose (see comment) burst over time. In order for the glass bottle to be tight at the top (neck), we had to replace it. Otherwise, every time you pour a drink, the liquid will get into the thermos. And finally it will flow out of the bottom cover.