I own several of this cup in multiple colors. It is the perfect size, fitting into my car's cupholder, standing up in my drawer-style microwave, and fitting neatly under the dispenser of my coffee carafe. It is microwave safe and dishwasher safe. The lid screws on and has an open sip hole. This is less secure than closable sip holes, but I also don't have to try to manipulate a sip seal while driving. The only one of 8 cups that has failed is the one that my daughter dropped onto concrete from height... it landed on the lid at an angle and the lid split. It wasn't leaking, but I was afraid it my start to leak unexpectedly in the future, so we threw the lid away.