HydroSensor IThe original! Map the migration of water in carpet and pad without straining your back. The HydroSensor I has a 31" reach to save your knees and posture. Sensitive nickel-plated points alert you to moisture content above 17 percent. Use only on carpet and pad. Saves your back with a 31" reach Stainless steel construction Nickel-plated, retractable points