FIIL Key is very balanced in terms of design, workmanship, sound quality, battery life, and functionality, and the overall cost-effectiveness is very high. As an entry-level bluetooth earphone, FIIL Key’s product strength is still very strong. However, for those who pursue sound quality, it is recommended to choose the high-end TWS earbuds under FIIL.

Appearance Design & Battery Life

FIIL Key is designed by German DA design studio. The charging case adopts the design idea of ​​round + square, with a round shiny metal in the middle, which is completely different from the stereotyped bluetooth headphones on the market, and is elegant and unique.

FIIL Key earbuds are semi-in-ear design, and sound quality is not the most important thing for entry-level bluetooth earphones. Because the gap in sound quality of bluetooth headphones at this price is not very large, and users who buy this price do not have high requirements for sound quality, but the experience is more important. The semi-in-ear design is more comfortable to wear and suitable for long-term wear. Even if the in-ear design with better airtightness is used, the sound quality will not be improved, so the semi-in-ear design is the best choice.

A single earbud weighs only 3.7g, which is very light and will not cause pressure on the ear canal. The reason why Apple Airpods can be purchased by so many people is inseparable from the lightweight volume and comfortable semi-in-ear design. A single earbud has two built-in Mic, and supports ENC dual-mic call noise cancelling. Both the left and right earbuds support high-definition calls, and also support IPX4 life waterproofing.

The FIIL Key earbuds can last up to 5 hours at a time, and if you wear it continuously for more than 5 hours, it is considered high-intensity use, so the battery life of this earbuds should be enough for most users. Moreover, with the charging case, the cumulative battery life is up to 24 hours.

Latency & Dual Device Connection

FIIL Key adopts the latest Bluetooth 5.3 technology, which makes the connection more stable and lower latency. Low-latency solutions have also been customized for three scenarios: games, music, and videos. It is no problem to cope with mainstream games and enjoy the synchronization of audio and video. In the process of using FIIL Key earbuds, I feel that its bluetooth signal coverage is very wide, and even if it is used through the wall, there has never been a disconnection, lag and other problems.

FIIL Key supports dual device switching. After connecting the two devices, long press the earbud for 4 seconds to switch freely between the two devices. There are a lot of touch functions, supporting independent control of dual earbuds, music play/pause, switching, volume adjustment, answering calls, etc. In addition, in the FIIL+ APP, you can adjust the sound effect, switch the touch mode and other operations.

Sound Quality of FIIL Key

I believe that many friends buy entry-level true wireless bluetooth earphones because they are cost-effective. Therefore, the sound quality requirements should not be very high, and it can meet the daily use of video, music, and games.

The FIIL Key earbuds use a 13mm dynamic titanium-plated diaphragm unit, which can retain the details of the sound well, which is rare in the tws earbuds in the same price range. Not only that, this true wireless earbuds also has a built-in sound-range dynamic diaphragm system, which has good sound quality whether it is used in daily use or playing games.

Personally, I feel that the sound resolution of FIIL Key is very strong, the treble is transparent and not harsh, and the mid-bass is loud and not dull. Not only that, but the instruments and vocals in the song are rich in detail, which is perfect for listening to pop songs.