Originally had one of these for a tea cup and was amazed at how much hotter my tea/coffee would stay using it. I work at home and often have my cup beside me, but get distracted and the coffee cools off before I get to drink it. This solves the problem. Glad to see someone offer them without a cup. I use them to keep things hot, keep bugs out of my cup when outside and to keep my dogs from trying to swipe a sip. Yuch! Good, heavy and solid lids.