The Flum UT Bar 50K, or UT 50K for short, is a rechargeable disposable vape with two separate flavor tanks in one body. It holds 17mL of 5% nicotine salt e-liquid, runs dual mesh coils, and delivers up to 50,000 puffs in Eco Mode. After three weeks of daily use, our verdict is simple. Buy it if flavor variety is your top priority. Look elsewhere if battery size or pocket space matters more.
Our rating: 4.2 / 5. Best for vapers who get bored of one flavor and want a fruit and a mint in the same device. Skip it if you want the biggest battery in the class or a slim stick.
Key Takeaways
- Two tanks, two coils: the only 50K device that switches flavors with one tap.
- Puffs: up to 50,000 in Eco Mode, about 25,000 in Turbo Mode. Real-world counts land closer to 38,000 to 42,000 per independent reviewers.
- Battery: 760mAh, the smallest in the 50K class. Plan on a daily USB-C top-up if you run Turbo.
- Flavors: 24 dual-flavor combos in stock at Vape City USA.
- Price: $17.99 at Vape City USA, $2 under most 50K devices in our catalog.
First Look at the UT Bar 50K
Flum released the UT Bar 50K in spring 2025 as its first 50,000-puff device. It's a wide, flat brick with a soft-touch back panel, a 2.01-inch HD screen on the front, and two small buttons on top. The screen is the best part of the design. It shows battery percentage, the e-liquid level of each tank, the active tank, and the current mode, all at once.
The squishy back panel doubles as a fidget pad. Customers like it more than reviewers do.
The trade-off for all that hardware is size. The device measures about 91 by 58 millimeters, and one reviewer's first con was "a bit bulky in tight jeans." It fits a jacket pocket or a bag without issue. If you want a slim stick, this isn't it.
How the Dual Flavor System Works
Each UT 50K holds two e-liquid tanks with their own mesh coil. One tap on the switch moves you from tank A to tank B. The two top buttons set the intensity of each flavor across three levels. Run one flavor bold and the other subtle, or shut one side off entirely.
Two flavors in one device: two tanks, two coils, one tap to switch.
In practice, this solves a real problem. A single-flavor 50K device asks you to taste the same thing for three or four weeks. With a fruit on one side and a mint on the other, you can reset your palate whenever you want. Every hands-on reviewer we read lands on the same conclusion: the toggle is useful, not a gimmick.
One habit matters. Alternate tanks instead of draining one side first. Empty tank A while tank B is still full and that coil runs dry and tastes burnt. The device still has plenty of juice and battery, but one side is done. Reviewers call this the "half a vape" problem, and it's avoidable.
Eco Mode vs Turbo Mode
The UT 50K has two power modes. Eco Mode is the everyday setting. It manages power for steady flavor and delivers the full 50,000-puff rating. Turbo Mode sends more power to the dual mesh coils for denser vapor and a bolder hit. It also cuts the rating to about 25,000 puffs.
We spent most of our three weeks in Eco Mode and switched to Turbo for the first few draws of the day. The difference is noticeable on the first pull: thicker clouds and a harder throat hit. Turbo also drains the battery fast, which brings us to the biggest complaint about this device.
The airflow slider tightens or opens the draw in either mode.
There's a third control most people miss: an airflow slider on the side. Close it for a tight, cigarette-style draw, or open it up for looser pulls and bigger clouds in Turbo Mode. Combined with the two power modes and the per-flavor intensity buttons, you get more ways to tune a hit than any other 50K disposable we've tested.
Battery Life and Charging
The 760mAh battery is the weak spot. For context, the VIHO TRX 50K carries 1,500mAh, and Flum's own newer UT Bar Pro 50K moved up to 1,100mAh. In Eco Mode, one charge covered a full day for us. In Turbo Mode, we were plugging in every evening.
Charging is USB-C and takes about 45 to 60 minutes from empty. There's no cable in the box, so keep a phone cable handy. The screen warns you with the battery percentage well before the device shuts off, which is more than most disposables offer.
How Long Does the UT 50K Really Last?
Flum rates the device at 50,000 puffs in Eco Mode. Independent testing by VapeObservation in August 2026 measured 38,000 to 42,000 puffs. That matches what we'd expect from any 50K device once you factor in longer draws and some Turbo use. Treat the 50K figure as a ceiling, not a promise.
In real weeks, that works out roughly like this for a 17mL tank:
- Light use (social, evenings): 5 to 6 weeks in Eco Mode
- Average daily use: 3 to 4 weeks in Eco Mode
- Heavy all-day use: 1 to 2 weeks, less if you live in Turbo Mode
Customers back this up. "Lasts longer than I expected" shows up in four of the nine rated reviews we found at other retailers. For a deeper look at how puff ratings translate to days, read our guide on how long disposable vapes last.
Flavor Combos: What to Pick
Vape City USA stocks 24 dual-flavor combos. Based on our own sales data from April to September 2026 and on reviewer consensus, these four are the safest picks:
- Banana Smoothie / Strawberry: creamy on one side, bright and fruity on the other. The most praised combo across reviews.
- Green Apple / Fuji Apple: sour crunch paired with sweet crispness.
- Blue Razz Ice / Triple Berry: cold blue raspberry next to a rich berry mix.
- Cool Mint / Icy Mint: a light mint and a deep freeze. Our third best seller by units.
Our top sellers by units are the Clear editions (Clear / Clear White and Clear / Clear), which are unflavored. If you're after a neutral hit, those are the ones. Cola Ice / Cherry and Root Soda / Vanilla are the dessert picks that keep coming up in reviews. Two combos got called "one-note" by reviewers: Watermelon / B-Pop and Sour Fab / Citrus Ice. They aren't bad, but they don't show off the dual-tank idea.
Flavor stays consistent through most of the device's life. Reviewers report strong output until roughly the last 20% of each tank, which is where the alternate-tanks habit earns its keep.
UT Bar 50K vs Other 50K Vapes
The UT 50K wins exactly one category in the 50K class, and it wins it outright: flavor variety. Everywhere else it's mid-pack or behind. Here's how it stacks up against the two 50K devices our customers cross-shop most.
| Feature | Flum UT Bar 50K | VIHO TRX 50K |
|---|---|---|
| Flavors per device | 2 (dual tank) | 1 |
| E-liquid | 17mL | 18mL |
| Battery | 760mAh | 1,500mAh |
| Coil | Dual mesh | Quad mesh |
| Price at Vape City USA | $17.99 | $19.99 |
The Beri Crush 50K is the other common alternative. It carries a 20mL tank, a quad mesh coil, and charges from 0 to 80% in about 15 minutes, for $19.99. We rated it 4.4 in our Beri Crush 50K review. If you want one flavor and the longest runtime, Beri or VIHO make more sense. If you want two flavors, nothing else in this tier does it. Our best 50K puff vapes guide ranks the whole field.
Pros and Cons
Pros:
- Two flavors in one device, with no cross-contamination between tanks.
- Adjustable intensity for each flavor, three levels per side.
- The clearest screen in the 50K class: battery, both tank levels, and mode.
- Smooth, consistent hits. "Smooth" shows up in six of nine customer reviews we read.
- $17.99 at Vape City USA, cheaper than most 50K devices in our catalog.
Cons:
- The 760mAh battery is the smallest in the class. Turbo Mode means daily charging.
- Real-world puff count lands around 38,000 to 42,000, not 50,000.
- Bulky. About 91 by 58 millimeters, so it's a jacket-pocket device.
- Uneven tank use can leave one coil dry while the other is full.
- No USB-C cable in the box, and only one nicotine level (5%).
Final Verdict
The Flum UT Bar 50K earns a 4.2 out of 5. It does one thing no other 50K disposable does, and it does it well. Two flavors, switched with a tap, with a screen that shows exactly where each tank stands.
The small battery and the size are real drawbacks, and newer 50K devices beat it on both. But if you get bored of one flavor by week two, this is the device that fixes that. Pick it up for $17.99 at Vape City USA, or browse the rest of the Flum lineup. To weigh it against every other big-puff option, see our disposable vapes collection.
Flum UT Bar 50K Review FAQ
Is the UT vape really 50K puffs?
Not quite in practice. Flum rates the UT Bar 50K at 50,000 puffs in Eco Mode and about 25,000 in Turbo Mode. Independent testing by VapeObservation in 2026 measured 38,000 to 42,000 real-world puffs. That's normal for the 50K class, where ratings assume short draws in the lowest power mode.
Are Flum vapes good quality?
Yes, based on the reviews we found. The UT Bar 50K averages 4.6 out of 5 across nine rated customer reviews at one major retailer. Independent reviewers scored it 8.0 and 9.2 out of 10. The common praise is smooth, consistent flavor and solid build. The common complaint is the small 760mAh battery.
What is the best Flum UT flavor?
Banana Smoothie / Strawberry is the most praised combo across reviews. Green Apple / Fuji Apple, Blue Razz Ice / Triple Berry, and Cool Mint / Icy Mint round out the top four. At Vape City USA, the unflavored Clear editions are the best sellers by units.
Are UT Bars a good device?
The UT 50K is a good device for one specific buyer: someone who wants two flavors in one vape. It has the best screen in its class and consistent flavor. If you'd rather have the biggest battery or the slimmest body, the VIHO TRX 50K or Beri Crush 50K are better fits.
How much does a Flum UT vape cost?
The Flum UT Bar 50K sells for $17.99 at Vape City USA. Online prices in September 2026 ranged from about $15.50 to $24.99 across a dozen retailers, with a median of $18.69. Brick-and-mortar shops often charge $24 or more.
How long does the Flum UT 50K last?
About 3 to 4 weeks for an average daily vaper in Eco Mode. Light users get 5 to 6 weeks, and heavy all-day use lands at 1 to 2 weeks. Turbo Mode roughly halves those numbers. The 17mL tank is split between two flavors, so alternate them to use the full capacity.
Does the UT Bar 50K come with a charger?
No. The UT 50K charges by USB-C, but there's no cable in the box. Any standard USB-C phone cable works, and a full charge takes about 45 to 60 minutes.
WARNING: This product contains nicotine. Nicotine is an addictive chemical. For adults 21 and over only. Specs are manufacturer ratings; real-world results vary with use.
