FINIS Duo Underwater MP3 Player

Quick take

The FINIS Duo Underwater MP3 Player is a swim-focused, waterproof bone-conduction audio device designed to let you hear MP3/WMA files during your workouts. When it works correctly, the underwater sound experience is repeatedly described as impressive, but multiple buyer reports point to charging contact and battery reliability issues over time.

Pros and cons

Pros

  • Underwater-focused bone conduction audio, designed to avoid earbuds-in-water issues.
  • Simple music navigation with MP3 and WMA support.
  • On-board flash storage (4GB) and up to 7 hours of battery life.
  • No screen (audio-first experience), which some swimmers prefer for in-water simplicity.

Cons

  • Buyer feedback includes charging-dock contact problems that can prevent charging and file transfer.
  • Some users report battery drain when not in use, shortening real-world usable time.
  • Durability concerns show up in reports related to small external parts and cable wear over extended use.

What buyers think

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Overall, buyer-review evidence is mixed. Many comments align on one theme: the underwater bone-conduction audio is strong and can make swim sessions more enjoyable than typical earbud alternatives. However, the same review set also points to recurring operational reliability concerns, especially related to charging. Some swimmers describe situations where the unit stops recognizing the charging contacts, leading to inability to charge or transfer music. Battery behavior is another recurring theme, with reports that the battery can drain faster than expected when the player is stored. On durability, feedback suggests the system works best when treated as a specialized, water-routine device, since small components (charging-contact areas, cable/rubber sections) may be vulnerable over time.

What the FINIS Duo is, and how it’s meant to be used

The FINIS Duo combines a waterproof underwater MP3 player with bone-conduction headphones intended for swim workouts. Instead of sealing earbuds in the ear canal, bone conduction transmits sound through cheekbones. That approach is popular with swimmers because it reduces common “earbud and water” headaches and can be more comfortable over long sessions.

Key features that matter for swimmers

Underwater audio via bone conduction

The system is designed for bone-conduction listening, which is central to the product experience. Buyers often describe the sound underwater as a standout strength, particularly for keeping pace during lanes and interval sets.

File support and storage

It supports MP3 media and is also compatible with WMA files. Storage is provided by 4GB flash memory, and the device works with a memory card format listed for the product category (Micro SDXC is shown). Practically, this means you can build a workout playlist and go without relying on a phone in the pool.

Battery life and real-world expectations

The listed battery average life is up to 7 hours. That figure is helpful for planning a typical session, but buyer feedback suggests some units may lose more charge when sitting unused, so it’s smart to consider routine charging before training if you go days between swims.

Battery-free distractions: no display

The device has no display, which keeps the in-water profile simpler. The tradeoff is that you’ll rely on the built-in interface for navigation, so it may be less convenient than display-based players when you want to quickly confirm track position mid-workout.

FINIS Duo Underwater MP3 Player pros and cons

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Pros

  • Underwater sound is a strong point for many swimmers. If your top priority is music while swimming, the bone-conduction design is often called out as delivering a genuinely satisfying underwater listening experience.
  • Works as an all-in-one swim player. With onboard storage and MP3/WMA support, you can bring music into the pool without having to mount or protect a phone.
  • Water-routine friendly form factor. The design is specifically intended for swim use, aiming to reduce issues like earbuds slipping or trapped water in your ears.
  • Battery life is rated up to 7 hours. For many training schedules, that can cover a workout or two depending on intensity and session length.

Cons

  • Charging-contact reliability can be a weak link. Multiple buyer reports describe failures related to the charging dock contacts, which can make the device hard to keep functional.
  • Battery drain during storage is a concern for some owners. If you swim irregularly, you may need to top up before sessions rather than assuming a full charge will last.
  • Extended durability may vary by use. Some buyers mention concerns about small external parts and cable wear over time, suggesting this is best treated carefully as a specialized water device.

Who should buy

Consider the FINIS Duo if you’re a regular swimmer who wants a waterproof way to listen to music during training and you value bone-conduction comfort over traditional earbuds. It’s also a fit if you prefer an in-pool dedicated player instead of bringing a phone into the water environment.

Who should avoid (or choose something else)

If your priority is maximum day-to-day reliability, especially regarding charging and storage, be cautious. Buyer experiences show that charging-contact issues can become a dealbreaker for some owners. Also, if you often forget to charge devices in advance (or have long gaps between swim sessions), the reported battery-drain behavior during storage may not match your routine.

Verdict

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The FINIS Duo Underwater MP3 Player is a compelling choice for swimmers who care most about the underwater audio experience and want an MP3/WMA player built for the pool. The biggest buying caveat is reliability, especially around charging contacts and battery behavior when stored. If you’re willing to treat it as a specialized swim device and keep charging habits consistent, it can be a very satisfying way to bring music into your workouts.

Price and availability

Check the latest pricing and availability for the FINIS Duo Underwater MP3 Player here: Buy on Amazon.

FAQs

Is the FINIS Duo Underwater MP3 Player waterproof enough for regular swim workouts?

It is designed as a waterproof underwater MP3 player for swim use. The practical expectation is that you treat it like a dedicated water workout device, with the understanding that charging and contact areas matter for ongoing functionality.

What audio formats does the FINIS Duo support?

It supports MP3 files and WMA files.

How long does the FINIS Duo battery last?

The battery is rated for up to 7 hours average life. Some buyers report faster drain when the unit is stored, so charging before a swim may be wise if you do not use it frequently.

Does it have a screen for track browsing?

No, it does not include a display, so navigation is handled through the device’s simplified in-water interface.

What’s the main downside people mention about this player?

The most notable theme in buyer feedback is charging reliability. Some users report issues with the charging dock contacts, which can prevent charging and complicate music transfer.

Is this worth buying if I swim occasionally?

If you only swim occasionally, consider the reports of battery drain during storage. You may need to top up the device before each swim session to avoid arriving at the pool with a dead battery.

Specifications

Product TitleFINIS Duo Underwater MP3 Player - Bone Conduction Swim Headphones - Waterproof Audio - 4GB - MP3/WMA Compatible - 7 Hr
CategoryElectronics > Portable Audio & Video > MP3 & MP4 Players
BrandFINIS
ManufacturerFINIS
Model NameFINIS Duo™ Underwater Bone Conduction MP3 Player
Model Number1.30.058.244
ColorBlack/Acid Green
Item Weight5.28 ounces
Additional FeaturesWaterproof
Connectivity TechnologyWired
Memory Storage Capacity4096 MB
Screen Size1.77
Compatible DevicesLaptop
Supported Media TypeMicro SDXC
Display Technologyno display
Supported StandardsMP3
Battery Average Life7 Hours
Item Dimensions D x W x H2.36"D x 5.91"W x 8.66"H
Built-In MediaFINIS Duo™ Underwater Bone Conduction MP3 Player
Global Trade Identification Number00616323202634
UPC616323202634
Mfr Part Number1.30.058.244
Item Type NameFINIS Duo™ Underwater Bone Conduction MP3 Player
Component TypeBattery
Unit Count1.0 Count
Special FeatureWaterproof
Media TypeMicro SDXC

Available variants

Color

  • Black/Acid Green

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