Water-proof microphone-speaker PMNN4040 is of protection class IP57 and is designed for use with portable radios of DP4000/ DP4000E series. Physical characteristic: Microphone type: Omnidirectional, Frame size: Small. Operational characteristics: Volume control: Not available, "Noise cancelling" function: Not available. Environmental requirements: Safety standards: UL-TIA4950/FM, Dust - / waterproof: IP57
