Dri-Eaz F251 HydroSensor II 

Easy moisture detection

Map the migration of water in carpet and pad without straining your back. The HydroSensor II has a collapsible shaft that extends to 31 inches to save your knees and posture. Sensitive nickel-plated points alert you to moisture content above 17 percent. Use only on carpet and pad.

Features:
Extends to 31" for use
Collapses to 21" for storage
Stainless steel construction
Nickel-plated, retractable points

Specifications:
Model:  251
Construction: Stainless Steel
Sensor Probe: Nickel-plated
Retractable: Yes