Portable Voice Amplifier with Headset Microphone,Personal Speaker Mic Recharable for Teachers,Tour Guides,Coaches Parameter: Signal to noise ratio: 45 Sensitivity: 90dp Effective frequency: 120Hz~15KHZ Distortion rate: 0.08% Amplification ran: 80 square meters Horn unit: 4 units Noise reduction technology: DSP intellint noise reduction Transmission distance: 200 meters Compatibility: Memory card, TF card, version: 5.0 Related Products:voice amplifier,megaphone,speaker with microphone,voice amplifier for teachers,bullhorn megaphone,voice amplifier wireless microphone,portable pa system,teacher microphone for classroom High Performance: Voice amplifier, more stable, better sound quality, low power consumption. DSP chip intellint noise reduction, good sound quality. Lar speaker, diaphragm sound amplification, easily penetrates and cover 80m², and the volume is increased by 90 times. 200M Transmission: Personal voice amplifier, 5W power is evenly amplified, with strong penetrating power, covering every corner easily. Various Wearing Methods: Portable voice amplifier, wired version, waist hanging/slanting hanging/snap buckle; microphone, head wearing hanging neck. Compatible, Disk, TF card, 3 modes can be selected. Dynamic Digital Display: Portable speaker mic adopts digital display, which can display various information such as function mode, volume receiving mode, and so on. Wide Application: Voice amplifier is very suitable for teachers, singing, coaching, training, presentation, tour guides and so on.