The FiiO FD3 Pro is an in-ear headphone featuring a dynamic driver and a semi-open acoustic design. The driver membrane is made from diamond-like carbon, a material that is almost as stiff as a diamond. The membrane is extremely lightweight and responds particularly quickly to impulses, allowing the FiiO FD3 Pro to reproduce music with fine detail and free from coloration. The membrane is driven by a magnet with 1.5 Tesla, providing very robust bass and excellent high-frequency resolution. The semi-open design enables a particularly natural sound, and by equalizing air pressure, it reduces pressure on the eardrum, preventing fatigue even after hours of listening. The FD3 Pro's housing is made from very lightweight aluminum and magnesium, and the top has been enhanced with 2.5D glass for a stunning look. The high-quality braided headphone cable features MMCX connectors and comes with two interchangeable plugs – 3.5 mm and 4.4 mm balanced – making it compatible with many playback sources. Good sound goes hand in hand with an optimal fit, which is why the FD3 Pro comes with various ear tips in different sizes and shapes, as well as with different sound signatures. Additionally, two interchangeable sound tubes are included for further sound customization: the larger black sound tube provides particularly detailed highs, while the smaller red sound tube delivers robust bass. You also receive a sturdy hard case to securely store and transport your headphones and accessories.