Damp Detector Features: 1) Audible signals detect the presence of damp and humidity 2) Operating voltage: DC 9V 6F22 battery Damp DetectorFeatures:1) Handheld instrument for detecting rising and penetrating damp in foundation walls, floors and timber2) Audible signals detect the presence of damp and humidity3) Operating voltage: DC 9V 6F22 battery (battery not included) Damp Detector