The Costablue Stainless Steel Travel Mug Your everyday companion — Flip to it with a Flip lid. Easy to clean. This larger-capacity travel coffee mug works hard so you don't have to — just flip the tumbler lid open and closed so it's sealed shut (and leak-proof!) when you're done sipping. Enjoy a hot cup of joe up to 7 hours after you poured it with select models, thanks to the doble wall vacuum insulation system on our Costablue model.