Our Dual Range Voltage Detector is designed for commercial and residential electrical applications. The expanded sensitivity range of 10-49V AC offers the ability to detect voltage in common systems that would normally go undetected when using a standard voltage detector. These systems include: LED Lighting, Fire Detection & Suppression Systems, HVAC Controls, and Security & Access Controls, along with many others. The Dual Range Voltage Detector detects and automatically differentiates 10-49V from the standard voltage range of 50-1000V AC. It does so by using uniquely colored LED indicators and audible tones, delivering the clearest indication of these two voltage ranges. The Dual Range Voltage Detector is a best-in-class voltage detection solution for any Electrician, Low-Voltage Technician or Facilities Maintenance Technician.