Perfect for keeping warm while you admire the night sky or for encouraging astral reveries while you wait for the sun to set, this Gateway to the Stars bottle will keep your drink hot (or cold) all day (or all night) long. Even on nights when your problem sets or data analysis keep you from finding dark skies filled with twinkling stars, this bottle is ready to be your companion. Fill it with your favorite brew and you’re ready for anything.

With a textured design for a unique tactile experience, this flask will keep your drink hot or cold until you're ready to enjoy it.

The science of how it works
Here's how it works: the space between the inner and outer flask wall is evacuated, creating a vacuum (well, a partial vacuum anyway...). In order for heat transfer to take place from the outside world into your cold drink, or from your hot drink to the outside world, it needs nearby molecules to excite. If there aren't many molecules nearby, as is the case in a vacuum, the heat's energy can't easily be passed along, so your drink stays close to the temperature it was when you put it into the flask for a really long time.

Simply stated, vacuums make great thermal insulation.

Details:
Width: 2.75"
Height: 8.27"
Opening: Wide mouth
Material: High-grade stainless steel, Lead-free
Cap Material: High-grade stainless steel
Hand wash only