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!

Replacement lids are sold as singles. All lids fit all sizes of stainless steel bottles. 

Materials: Stainless steel
Gasket: Silicone
Straw, flip lid & threading: BPA-free plastic

USA

Flat Rate $7.95
Orders $40+ ship for free

This product is made especially for you as soon as you place an order, which is why it takes us a bit longer to deliver it to you.  Your order may be sent in multiple shipments.  Made-to-order items cannot be shipped with expedited shipping.  You will receive shipping confirmation and tracking details for each portion of your order as it ships.  Apparel shipping times vary.

Wallpapers are printed to order and cannot be returned.

*December 11th

Last day to place orders for apparel (Such as t-shirts, hoodies, baby-suits, and aprons).

International

Shipping is available to most countries. See details at checkout.

If you're shipping to Europe, Asia, the Middle East, or Oceania, please check out our European website for lower shipping rates and quicker delivery times.

Shipping FAQ • Returns FAQ