20-Ounce Coffee Flask with Flex Sip^™ Lid

[This review was collected as part of a promotion.] I bought these for my daughter and her future husband who live in Montana. I was going to give them as Christmas presents however the temperature has been in the single digits already this year. I could not see them waiting for a full month before they could open them. I told them if they didn't like them I would take them back and use them myself however I was told that there would be a fight if I tried. They both love their drinking cups one for coffee and one for hot tea.

Yes, we have the cap installed correctly, red gasket flat side up, concave indentation side down. Worst lid cap I have ever seen. It takes first place. YouTube reviews never tell you this lid is a pain to take apart. Getting to the closed red spot, which blocks liquid, isn't easy, but it is doable. But sliding it past that point to the left to unlock the cap takes a very strong grip and power. You don't have much to hang on to either. Twisting it back on isn't any easier. It's almost like you are going over a plastic hump, a end stopper at the left of red close position. Maybe we got a bad lid, I don't know. What I do know. We can't use this thing. My wife can't twist it off, and I can just do it, this is insane. You really despise cleaning this thing. Just going to buy something else. I'm not even going to buy another lid for this thing. I am not a happy camper. I suggest you try one in a store first, especially if you are female as I purchased this for my wife. Unfortunately, we had to order an in-store delivery because it wasn't in stock, so we didn't try to take it apart before purchasing.