Dear friend,
The EM5 uses a 14.2mm beryllium-plated diaphragm dynamic driver specially chosen for its light and thin but also extremely rigid properties, allowing for robust bass and well-extended treble.
The EM5 is 3D printed with skin-friendly resin material certified as IIA grade by the EU. The entire shell is glossy, with great durability and anti-discoloration ability. It is comfortable to wear even for a long time.
Open earbuds are born naturally with a wide soundstage, yet with the shortcoming of bass signals easily exposed. In order to minimize the loss of the bass signals, the EM5, being printed with 3D technology, is designed with acoustic tubes and bass pipes that can greatly keep its independence, to finally lay down the foundation of low frequencies with deeper extension. To acquire better bass performance, it is recommended to couple the EM5 with foam ear tips.
And due to individual preferences, you could read the professional reviews and comparisons, as well as try out by yourself.
Our sellers' list:
https://www.fiio.com/wheretobuy
Review page of EM5:
https://www.fiio.com/em5_reviews
Best regards