Xtenzi Pioneer CPM1064 MIC ASSY Bluetooth Hands Free Microphone with Clip Xtenzi Replacement mic Microphone for Pioneer car sterio ,high sensitivity , low impedance , anti noise and ant jamming capability , Standard Operation Voltage: 4.5V Operation Voltage: 1.0V-10V.DC Wire Length: 4 M with fast and accurate data transmission, which could guarantee the voice clearly and stably under kinds driving occasions, it's highly improved the speech quality of hand free car kit communication system.