Model Number: HX-508-#1586 Key Specifications/Special Features: Adjustable neck ring allow for ideal fitTactical heavy duty throat microphone cutting down and keep noise from outside environmentDual throat microphone provide highest quality transmit audio possibleTransparent acoustic tube earphone provides privacy and discreet communication for any surveillance purposesEasy changeable acoustic tubeVOX PTTSpeaker:Speaker size: 12mmSound pressure level: 103dB±3dBImpedance: 32Ω±15%Audio output: 100mWMicrophone:Size: 9.7*5mmFrequency responses: 20-16,000HzSensitivity: -40dB±2dBImpedance: 2.2K Ω