Transiet Prtoection Design surge protection protects damaging microphone pathways that leave or enter the building. 

 TPD-xxSLPyy (Example TPD-24SLP4 which is a 24V, 4 wire protector)
XX = Operating Voltages 10V, 15V, 24V, 48V, 120V and 190V
YY = 2, 4, 6, 8, 10 and 8-RJ45
Max Amperage: 400mA
Max Data Rate: 10Mbps
Response Time: < 1 nanosecond
Strength: 16kA per pair
Ten Year Unlimited Free Replacement Warranty
Series Resistance: < 0.1 ohm
Enclosure Type: High impact, Non metallic
Din rail or screw down mountable

Protect outdoor microphone pathways back to audio equipment.  For two or three wires between 1 and 14V max use the following.