1. Upgrade tuning nozzles， for different musical styles The bass and balanced nozzles allow users to tune its audio settings by switching different nozzles. Bass for a bass-enhanced experience， Balance for full-spectrum smoothness. 2. Innovative T shaped pole piece driver unit The all new driver unit effectively eliminates the negative pressure in driver， providing clear， soft feel of sound and better extension of vocals. 3. New vibrant PEK diaphragm With extremely sensitive and fast response force， this KZ ED9 headphone has purer vocals， dynamic texured bass. 4. Musical instruments level acoustics brass housing The copper housing enhance the resonance effect， the tone is clearer and brighter， reproduce the fresh thorough and extremely dynamic sound. ED9 with bright silver chrome plated surface， simple and textured. Style:In-Ear Connectors:3.5mm Use:Mobile Phones/computers/mp3/mp4/tablents Function:Noise Cancelling，Microphone Model Number:ED9 Sound principle:Moving coil Frequency Range:7-46200 (Hz) Impedance:18 () Sensitivity:106 (dB) Cable length:1.2 (m) Speaker diameter:6.8 (mm)