Name: TRUTHEAR ZERO:RED Driver: 10mm + 7.8mm Dynamic Driver Diaphragm: Polyurethane Suspension LCP Liquid Crystal Composite Diaphragm Impedance: 17.5Ω±15% @1KHz Sensitivity: 117.5dB/Vrms @1KHz THD: <1%@1khz Frequency Response Range: 20-40.5kHz (IEC61094, Free Field) Effective Frequency Response Range: 20-20kHz (IEC60318-4, -3dB)