\"The Knock Box\" Knock Listening device (Single Channel )

The simplicity combined with the clarity of the \"The Knock Box\" makes this an indispensable mapping tool whether you are an occasional rolling road user, mapping in car or a professional calibration engineer. The Single Channel \"Knock Box\" Features; Adjustable Fequencey, High quality power and sensor looms (Included), Tough extruded alloy case, High quality noise reduction aviation headset and a wide band knock sensor (included).