- Unit: 9.2mm large Dynamic drivers + Customized medium and high frequency Balanced Armature drivers Plug Type: 0.78mm double needle Plug diameter: 3.5mm Frequency range: 20Hz-20000Hz Sensitivity: 110dB(±0.05dB) Noise reduction: 26db Impedance:24Ω Wire: Four-core silver-plated wire/microphone Technical Features:Separate lumens and catheters Craf: 3D printing