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Separate chambers
A permanent divider prevents flavors and liquids from mixing.
Splitflask: the patented two-drink tumbler
One cup. Two drinks. Finally.
The tumbler for people who always carry two drinks.
- Two sealed 15 oz chambers
- Independent hot and cold insulation
- Leak-resistant seals and cupholder-friendly
Rated 4.9 Stars by verified Splitflask customers
Hot
+
Cold
2 × 15 oz
sealed chambers
Free US shipping on ALL tumblers
30-day guarantee to try it
Patented design built to last
The two-drink tumbler people are talking about
Patented dual-chamber design
A smarter way to carry both
Your two favorite drinks. Not mixed.
Splitflask turns a two-bottle routine into one clean, one-handed carry—without making you choose between caffeine and hydration.
Separate temperatures
Independent insulation protects each drink's temperature.
One easy carry
One tumbler, one cupholder, and one free hand.
See it in action
30oz Dual-Chamber Tumbler
Two sealed 15 oz chambers in one 30 oz tumbler
Independent insulation keeps each drink at its own temperature
Leak-resistant seals, BPA/BPS-free, cupholder-friendly, and top-rack dishwasher safe
$56.00 USD
Regular price
$56.00 USD
How it Works
1. Fill both chambers
Pour one drink into each 15 oz chamber.
2. Align the lid
Place the straw over your cold drink and the spout over your hot drink.
3. Sip either side
Flip the straw or open the spout to enjoy each drink independently.
Real-world ways people use Splitflask
Customer Stories
Invented by a NICU Nurse
During long hospital shifts, co-founder Cheryl kept facing the same choice: bring coffee or bring water. That everyday frustration became Splitflask—a practical way to carry both without juggling two containers.
The Science & Design
Behind Splitflask is patented engineering that combines two fully insulated chambers into one bottle, allowing you to enjoy hot and cold drinks side by side.
The honest FAQ
Questions worth asking before you buy
The best FAQs are the questions people are afraid to ask. Here are the honest answers.
Before you buy
Is Splitflask for everyone?
Honestly? No.
If you're looking for a cup that keeps a drink untouched for 8+ hours, there are better options.
If you're tired of carrying two drinks everywhere, that's exactly why Splitflask exists.
Does the straw-and-spout lid come with the tumbler?
Yes. Every 30 oz Splitflask includes the dual straw-and-spout lid.
You only need to purchase another lid if you want an extra or replacement.
What materials are used?
The vacuum cup is food-contact stainless steel. The included lid system is made with polypropylene, silicone, and Eastman Tritan™ copolyester.
Drink-contact components are BPA- and BPS-free. Every current color/SKU uses the same tested materials. See the independent testing summary.
The big question
Why would I want two drinks in one cup?
Because most people already carry two drinks.
- Coffee + water.
- Electrolytes + hydration.
- Pre-workout + water.
- Tea + water.
Splitflask lets you carry both in one place instead of juggling two separate containers.
Do the drinks mix together?
No.
Each drink sits in its own chamber.
The only requirement is that the lid is aligned with the center divider when you close it.
Once aligned correctly, both drinks stay separated.
Does it leak?
Splitflask is safe for loose-bag transport when the lid is fully secured, the center seal is aligned with the divider, and both the straw and spout closures are completely shut.
Wipe away any liquid around the lid before packing it.
Temperature questions
Can I put a hot drink on one side and a cold drink on the other?
Yes.
That's one of the most common ways people use Splitflask. With hot and cold together, expect the hot side to last 2+ hours and the cold side to last 4+ hours.
Coffee + water is one of our customers' favorite combinations.
Will the hot side affect the cold side?
Over time, some temperature influence is normal.
You're carrying a hot drink and a cold drink in the same container.
With one hot and one cold drink, expect 2+ hours on the hot side and 4+ hours on the cold side. The tradeoff is convenience: one cup instead of two.
Actual retention varies with starting temperature, fill level, ice, room temperature, and how often each side is opened.
Is this a replacement for a high-end thermos?
No.
This is a two-drink solution.
It's built for people who want to carry two drinks in one cup—not people trying to keep coffee untouched all day.
Size & weight
Is it heavy?
The 30 oz Splitflask weighs 1.5 lb empty and approximately 3.3 lb with both chambers filled.
It's heavier than a standard tumbler because it's built to replace two drink containers with one.
Will it fit in my car's cup holder?
The base is 3.02 in (76.7 mm) in diameter. Cupholder sizes vary, so compare that measurement with your vehicle for the best fit.
The tumbler is 9.39 in (238.5 mm) tall, and the lid measures 4.42 × 3.97 in (112.3 × 100.8 mm).
How much does each side hold?
Each chamber holds approximately 15 oz.
Together, that's 30 oz total.
Cleaning
Is it dishwasher safe?
Yes.
Top rack is recommended.
Is it difficult to clean?
Not at all.
Most people use:
- Dishwasher
- Bottle brush
- Straw brush
Like any insulated tumbler, occasional deep cleaning is recommended.
Using it
Is there a learning curve?
A tiny one.
The biggest thing to remember is aligning the lid correctly with the divider.
Most people figure it out after their first use.
Can I use two cold drinks?
Absolutely.
With two cold drinks, expect up to 6 hours of temperature retention.
Many customers use:
- Water + electrolytes
- Sparkling water + still water
- Two different flavored drinks
Can I use two hot drinks?
Yes.
With two hot drinks, expect up to 4 hours of temperature retention.
You can use both sides however you'd like.
Can I use one side and leave the other empty?
Of course.
You're not required to use both chambers.
Shipping, warranty & support
What if I don't love it?
If you buy through Amazon, Amazon's return policy applies.
If you buy through Splitflask.com, see our return policy page for current return options.
How long does US delivery take?
Orders process in 1–2 business days. After shipment, standard US delivery typically takes 3–5 business days and includes tracking.
Every tumbler order includes free standard US shipping. Rates for accessory-only orders and international destinations are shown at checkout.
What does the one-year warranty cover?
The Splitflask One-Year Limited Warranty covers eligible defects in materials and workmanship under normal use for the original purchaser.
It covers the tumbler and the components included with it. Proof of purchase is required; the warranty page lists exclusions and claim steps.
What if something arrives damaged?
Email hello@splitflask.com with your order number, a description, and clear photos or video. We will review it under the one-year limited warranty or the applicable delivery policy.
How quickly do you respond to support requests?
We typically respond within 24–48 business hours.
Real humans read every message.
The question nobody else asks
What's the catch?
Every product has tradeoffs.
Splitflask's tradeoff is simple:
It's larger than a regular tumbler and takes one use to learn.
In return, you stop carrying two drinks everywhere.
Most people decide that's a trade worth making.
