MILTONPlain Lid 500 Thermosteel 24 Hours Hot and Cold Water Bottle, 1 Piece, 500 ml, Silver | Leak Proof | Office Bottle | Gym Bottle | Home | Kitchen | Hiking | Trekking | Travel Bottle

I'm a bit of a skeptic when it comes to those '24-hour' claims, but I figured, why not? My old flask was basically just a fancy cup at this point.I can tell it's made of good quality stainless steel. It's got a nice weight to it, not flimsy at all. The plain lid is simple, which I actually prefer. No fancy gimmicks, just a good, tight seal. And let me tell you, that seal works. I've tossed it in my bag, shoved it in my car, and not a single drop has leaked. Huge win!Now, for the real test: The temperature. I filled it with piping hot coffee around 7 AM one morning. By lunchtime, I was expecting it to be lukewarm at best. But nope! Still steaming. I was genuinely surprised. Then, just to see how far it would go, I left a bit in there until late afternoon. Guess what? Still hot, though admittedly not scalding. It was more than drinkable though.Then I tried it with ice water on a hot day. I filled it up in the morning, left it in my car while I ran errands, and by the afternoon, it was still refreshingly cold. Not just cool, but cold. That's pretty impressive.