Volume | 18 oz / 500 mL |
Width | 2.75" |
Height | 8.75" |
Opening | Wide mouth |
Material | High-grade stainless steel |
Cap Material | High-grade stainless steel, silicone ring |
Care | Hand wash (do not wash in dishwasher) |
Fill it with your favorite mulled hot cider or cold brew, and even if you don't get around to drinking it for hours, you can expect to find your beverage ready and waiting for you at just the right temperature. The metal cap seals tightly, so it won't leak all over your bag.
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!
USA
Flat Rate $9.95
Orders $75+ ship for free
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International
Shipping is available to most countries. See details at checkout.
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Great birthday present
My daughter loves this!!!
Very good quality.
Very good quality. It really keeps your beverages cool for quite a long time. Will be back to buy more soon.
My friend loved it!
My friend loved it! The item reached earlier than expected too! Thank you!

Love it!
It's very sturdy and hasn't dented even when I dropped it. The design is lovely!
Star Chart Stainless Steel Vacuum Flask
Absolutely beautiful bottle! I've purchased items from this shop many times and they've always been very beautiful and high quality.

birthday present
My friend loved this flask…it’s the second time I’ve sent one as a birthday present…they are a hit!

Love this!
I got this water bottle for myself a few months ago, and it has been AMAZING soon far! It keeps my water cold, it's easy to hand wash, and the texture acts as a satisfying fidget for my hands. I ended up buying two more as birthday gifts to family members. 10/10 recommend. :)
So beautiful.
So beautiful. Excellent quality and has a beautiful texture that feels amazing in the hands <3 thank you so much!

Star chart flask
This was a purchase for a Christmas gift. My niece loves it. She recently is studying the solar system.
Star Chart Stainless Steel Vacuum Flask
This bottle is absolutely stunning. I bought it as a gift for my dad, and while it definitely made a great Christmas gift, it's so nice that I almost wish I had bought one for myself too! I've purchased a few things from Cognitive Surplus at this point, and they never disappoint. Their designs on all of their products are always intricate and gorgeous, and they don't skimp on quality of materials either. If it's not clear, I highly recommend their products. I only wish that they made things for other interests, such as literature or history!