Uhf wireless beltpack transmitter d04 channel70 operating frequencies 64 selectable channels 4 banks of 16 single aa battery with upto 10 hours operation low battery indicator built in antenna 35mm 18 mini jack socket frequency response 100hz 15khz max input level 14db to 29db 0db1v optional unidirectional yp m5300 amp omnidirectional yp m5310 lavalier microphones colour black frequency response max 15khz frequency response min 100hz sound level spl 110db weight