These handsets are mainly used for outdoor telecommunicationswith waterproof and weatherproof features. For the outdoor industrial telephones, we could supply the matched handsets with UL approved Cheimei ABS material, anti-UV Lexan PC material, Carbon-loaded material and flame resistant material to meet different market demand.We also have different type microphone and speaker, like hearing-aid speaker, high-magnetic speaker and regular dynamic speaker with different resistance; For microphone, we have electret type, dynamic type, carbon-equivalent and noise reducing microphone for different filed.