Goodful Travel Mug, Stainless Steel Insulated, Double Wall Vacuum Sealed Coffee Cup with Leak Proof Lid, 14 Ounce, Gray

Q: Can I put this mug on a cup warmer for extra heat?

The Goodful Stainless Steel Insulated Mug should not be used on a cup warmer.

Q: The screw on lid looks thick. Will that affect how much coffee I can put in this 14 ounce mug?

It is very thick and difficult to screw on with a hot beverage. It is also almost impossible to close it once you open it to take a sip. Personally, I was sorry I bought it. I went with a Contigo, I can put 12 oz in with plenty to spare, set the top on and I'm ready to go. I love it, keeps coffee hot. It's an 14 oz mug which will hold pretty much 14oz. My pod Keurig only makes 12 oz. I only make a pot on the weekends. Hope this answer helps.