Review on Flex Sip Lid for Hydro Flask Wide Mouth Bottles by Nathan Tsugawa

This is an excellent lid, an improvement over the standard flip lid except for one major issue which causes it to leak a bit. Plastic edges fray and wash small pieces of rubber into the drink (this was my problem with the standard flip top - rubber pieces were showing after a year of heavy use), this lid seems to be much more durable - it opens by twisting, not pressure - no additional fuses required. I'm pretty sure it won't rotate in my backpack. Bad: - There is a large cavity in the lid that fills up when drinking when the lid is closed. , causing the void to detach from the bottle, but if you turn the bottle upside down the void will still flow into your bag! - The cavity is difficult to empty, there is always some liquid left that spoils and leaves dirt - I drink a lot of coffee with sugar and milk, it's not nice and it smelled. See photo of cap with top removed after use - all liquid visible there is free to drain out and the rest of the vial is sealed.