Avantro 17-Ounce Stainless-Steel Vacuum Bottle, Onyx Metallic The push -button pour-through stopper pops up for convenient pouring, closes tightly when the cup is attached, and will not leak. The steel cup is plastic lined. With vacuum insulation, the outside of the bottle stays cool, while the beverage inside keeps hot for up to 10 hours or cold for 20 hours.