PMMN4039 - Motorola Noise Cancelling Remote Speaker Microphone with 3.5mm Audio, IS/FM -- HT750, HT1250, HT1550, PR860, 

MTX850, MTX950, MTX8250, MTX9250 - The Windporting feature of this microphone helps lessen background noise from high winds 

and other severe weather conditions. Audio can pass through the speaker grill even when the microphone port is blocked by water. 

Now public safety professionals can be more confident than ever of clear, understandable communication when Mother Nature is 

uncooperative. The Windporting Remote Speaker Microphones allow talking and listening without removing the radio from the belt or 

case.