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The Most Advanced
Truly Wireless Earphones

Probably the "cleanest headphone" you can buy, Duo features unique JIS-compliant lifetime antibacterial protection that ensures the highest degree of hygiene for your long term enjoyment.

The long-anticipated Qualcomm® TWS Plus™ allows both the left and right earphones to receive audio signal directly from the phone without going round the skull, resulting in vast improvements in wireless stability and energy saving. It is also the worlds's first Truly Wireless Earphone to simultaneously offer Wired connectivity for use in all situations.

  • Unique lifetime antibacterial protection meeting Japan Industrial Standard JIS Z2801 for effectiveness

  • Unique dual Truly Wireless and Truly Wired connections via BT and MMCX connectors

  • Expert sound tuning with 40,000Hz Composite Drivers meeting the stringent requirements for high resolution audio, with native AAC/aptX™ support

  • The latest Qualcomm® QCC3026 TWS engine with TWS Plus™ for best wireless performance with independently left/right channel reception

  • 8-hour playtime on a single charge with 15-min Turbo Charge for 2 hours' play

  • Oxygen-free cable with conference-quality mic




The Best of Both Worlds


Probably the best thing since the Wireless Headphone, the new Duo combines the convenience of a Truly Wireless Earphone and the flexibility of a Wired Earphone for unprecedented freedom. The highly-anticipated Qualcomm®  TWS Plus offers truly independent L/R reception, while JIS-compliant Antibacterial Protection gives you perfect peace of mind.



World’s First Antibacterial Protection#1

Earphones are personal devices that we come to close contact with, it is therefore important that they stay clean especially at a time of health crisis. We have made the Duo virtually germs-free by adding antibacterial protection that lasts a lifetime thanks to a special process that fuses the agents into the plastic instead of a mere coating that could come off with use. The advanced antibacterial formulation meets the stringent requirements of Japan Industrial Standard JIS Z2801 for safety and effectiveness.

Duo is a Truly Wireless Earphone with MMCX connectors, meaning you can use it as a Truly Wireless Earphone or plug in a cable and use it as a Wired Earphone. Use Truly Wireless for the gym#2, commuting or just casual listening; and Wired for things like:




Inflight Entertainment

While some newer aircrafts allow wireless headphones, the majority don’t. With Duo you can use it with the included MMCX cable to enjoy music from your phone.


You can also plug it into the aircraft’s entertainment system to enjoy inflight movies, music and shows. Special sound tuning with emphasis between 1kHz and 3kHz ensures vocals and dialogue stay clear against engine background noise in wired mode.


It all happened to us before: you wanted to watch a video on your laptop and only to find that you forgot to charge your wireless earphones! With Duo the cable takes over without the need for any power. When not in use, it can be stored in the included case so it’s always ready. 

Media Players

In the digital world music comes in various formats, and not all of them are wireless-friendly such as those high resolution lossless types. With Duo not only can you enjoy them in their original quality through wired connection but also have the freedom to upgrade to low-interference Balanced cable using its MMCX connectors to get the best result from a compatible media player.     


At its Best


Qualcomm® TrueWireless™ Stereo Plus with aptX™ audio


Duo features Qualcomm’s latest QCC3026 BT engine offering not only the best Truly Wireless audio thanks to native AAC and Qualcomm aptX™ audio, but also the highly anticipated Qualcomm TrueWireless™ Stereo Plus (TWS Plus) that enables direct reception of the left and right channels from a compatible phone#3, instead of taking the stereo signal by one of the earphones (the “master”), splitting it into left and right channels and sending one of them to the other earphone (the “slave”) to re-generate the stereo sound, which is how all current Truly Wireless Earphones work.

TWS Plus greatly improves the user experience with stable wireless reception, low latency and long playtime because instead of travelling around your skull (which is not easy!), wireless signal now travels more easily and directly from your phone to both earphones without the need for “re-routing”. This, together with the superior power management of QCC3026, provide the Duo with an extra long playtime of up to 8 hours on a single charge#4 - enough for your whole day’s calls and entertainment!

Qualcomm TrueWireless is a product of Qualcomm Technologies, Inc. and/or its subsidiaries.

Qualcomm aptX audio is a product of Qualcomm Technologies, Inc. and/or its subsidiaries.

Qualcomm is a trademark of Qualcomm Incorporated, registered in the United States and other countries.

Qualcomm TrueWireless is a trademark of Qualcomm Incorporated.


At FL sound quality always comes first. That’s why we put the same focus on Duo as our other products with advanced speaker technology and sound tuning expertise to deliver the most entertaining musical experience. 

40000Hz Composite HD Drivers

Traditional drivers are prone to residue vibrations that could cause distortions. Our new 6mm High Definition Drivers are made of advanced composite materials for their rigid and anti-resonance properties that enable fast and accurate signal response, resulting in clean and undistorted sound. Its high rigidity also means the diaphragm can be made extremely thin thereby capable of producing frequencies up to 40000Hz#5 for the best audio quality.

Expert Sound Tuning

Duo’s sound profile is tuned by one of the world’s top acoustic architects, with a lively sound signature encompassing an expansive soundstage, tight solid bass, warm vocals and crisp, extended treble for a thoroughly entertaining musical experience.

Audiophile-grade OFC Communication Cable

The included cable is made with oxygen-free high purity copper for near lossless signal transfer, while the built-in conference-grade microphone with volume control#6 is ideal for business calls.



Full Touch Control

Touch Control offers the best balance between comfort and functionality. The Duo features our signature interface, with an intuitive “left down, right up” logic. For example to increase volume touch and hold the right earphone - or the left to decrease: simplicity at its best.

15-Minute Turbo Charge

A quick 15 minute charge provides about 2 hours#4 of use - ideal when you are in a hurry.


Around You

Duo Specifications

Wireless Standard: BT5.0/Qualcomm® QCC3026 with Qualcomm TrueWireless™ Stereo Plus

Supported Codec: SBC, AAC, Qualcomm® aptX™ audio

Frequency Response: 20Hz - 20,000Hz (Wireless mode), 20Hz - 40,000Hz (Wired Mode)

Speaker Type: 6.2mm Composite HD Full-Range Dynamic

Wired Connection: 1.2m MMCX Oxygen-free Cable with Mic and Volume Control

Battery Capacity - Earphone: 60mAh Li-Ion

Battery Capacity - Charger: 500mAh Li-Polymer

Weight - Earphone (each): 6g

Weight - Charger: 47g


Specifications are subject to change without notice

Qualcomm TrueWireless is a product of Qualcomm Technologies, Inc. and/or its subsidiaries.

Qualcomm aptX audio is a product of Qualcomm Technologies, Inc. and/or its subsidiaries.

Qualcomm is a trademark of Qualcomm Incorporated, registered in the United States and other countries.

Qualcomm TrueWireless is a trademark of Qualcomm Incorporated.

In the Box
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The Large Prints

We believe in providing product information in the most transparent manner. Please read the following details to learn more about capabilities of the Duo:

#1 World's first Truly Wireless Earphones to feature antibacterial treatment as of 1 June 2019

#2 Not sweat or waterproof. Use with care. Avoid contact with excessive sweat or fluids.

#3 To enjoy the benefits of Qualcomm TrueWireless Stereo Plus (TWS Plus) a compatible phone supporting dual channel transmission is required, such as those using Qualcomm's Snapdragon 845 processor (model dependent - check with your phone's manufacturer for details). For phones that do not support dual channel transmission, TWS Plus still offers advanced energy saving by automatically pairing with the earphone (left or right) that has more power to better manage battery performance.

#4 Formula-Lab’s test. Actual performance may vary according to temperature, volume and content. Battery life may decrease with time and usage

#5 In wired mode only. In wireless mode the frequency response goes up to 20000Hz

#6 Some or all of the phone control features may not work with some phones, especially those that use a 3.5mm earphone adaptor. Please try with your phone before purchase

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