HydroSensor IIMap the migration of water in carpet and pad without straining your back. The HydroSensor II has a collapsible shaft that extends to 31" to save your knees and posture. Sensitive nickel-plated points alert you to moisture content above 17 percent. Use only on carpet and pad. Extends to 31" for use Collapses to 21" for storage Stainless steel construction Nickel-plated, retractable points