I went through a couple of these and found them more frustrating than not. In the end I ended up with a Yeti 14 oz mug. If you don't mind drinking from stainles

I went through a couple of these and found them more frustrating than not. In the end I ended up with a Yeti 14 oz mug. If you don't mind drinking from stainless steel, it (like all thermoses) does a really good job of keeping warm things warm and cold things cold. https://www.yeti.com/drinkware/mugs/mug-14oz.html https://www.yeti.com/drinkware/mugs/mug-14oz.html