Ultrasonic Leak Warner and Transmitter Quick location of Air,Water,Dust leaks with Earphone Receiver : Notifications Indication : The "LEAK" LED lights and the "ticking tone" increases in frequency / Frequency Response : 40kHz 2kHz Length of testing rod : 134mm Transmitter : Indicator : LED / Output Frequency : 40kHz Power Supply : 1 x 9V(6F22) battery (included) Battery : 9V,6F22 or equivalent