Sonin Tests For Presence Of Damaging Moisture. Contact Probes On 3' Coiled Cable. Dual Reading Scale Provides Relative And Moisture Percentages 10% - 28% Readings. Uses 9 Volt Battery. Instructions Included. Tests Hard Or Soft Wood, Concrete, Plaster And Carpet. Locate And Trace Roof Leaks, Water Seepage. Check, Surfaces Before Painting, Laying Floors Or Tile, Wallpapering. Select Drier Lumber.