Review on 🍶 Set of 6 Glass Water Bottles, 18oz for Juices and Beverages - Stainless Steel Leak Proof Caps with Carry Loop - Includes 6 Black Nylon Sleeve and Cleaning Brush for Better Convenience by Ryan Turner

So the bottles themselves are absolutely beautiful as are the cases. However, there is a small silicone ring on the top that ensures a proper seal and makes them waterproof. Unfortunately, if you open the bottle carelessly, these little rings fall out and it's easy to lose one or drop one on the floor. I told the seller and he said he would try to improve the quality so it can be assumed this is a known issue. It's still a good product with the caveat that you don't want to lose those rings. Without them, the bottles are no longer watertight and thus practically unusable.