Fosi Audio IM4 Open‑Back In-Ear MonitorDual Magnet & Dual Chamber for Hi Fi Sound: Experience audiophile clarity. Our IEM earphones feature an N52 dual magnet for powerful control and a dual chamber design for balanced sound,The 10mm beryllium driver delivers wide soundstage and crisp details. Balanced & Fatigue Free Tuning: The open back design and acoustic damping wool reduce resonance and harshness, creating a relaxed, wide sound. The hifi earbuds are expertly tuned for balanced bass,

please confirm with the amplifier manufacturer

Compact Yet Powerful: Crafted with a CNC-machined aluminum alloy body

Noise Cancellation: Noise Cancellation reduces background distractions like keyboard clicks and fan noise with up to 40dB deep noise reduction

an 18-month worry-free warranty

sending only mids and highs to main speakers while routing bass through the SUB-OUT—enhancing clarity

Bluetooth Antenna x1

Long Battery Life: Powered by a robust 1200mAh lithium battery

making them ideal for audiophiles

Headphones Frequency Response Standard RIAA THD ≤ 0

setting IEMs apart in both style and substance

The dual PCBA separated design ensures that the input and output signals do not interfere with each other

MM Phono Preamplifier & DC12V Power Adapter: Output Voltage Level: 2V max (P-P) at 10K Ohms