Equipped with productive communication helmet factory and company, Fenghuo Hongsheng is one of the leading China communication helmet manufacturers and suppliers. Welcome to contact us.Model FHH-1 Communication Helmet is composed by helmet, communication cap and adapter cable. It is an audio terminal used in various communication cars.Main Technical Specifications:Operation temperature: -40℃～+65℃Weight≤1900g (whole set)Transmitting impedance: (150±22.5)Ω(1000Hz)Transmitting sensitivity:(-63±3)dB/Pa(200～4000Hz,1V for 0dB)S/N≥8dB Receving impedance: (500±100)Ω(1000Hz)Receving sensitivity:(98±3)dB/mW(200Hz～4000Hz,20μPa for 0dB)Sound insulation amount of earmuffs≥20dB(125Hz～8000Hz)