The Tork ZS124 Stem Mount Instant Response Led Photocontrol Light Sensor Provides A Simple Way to Control Residential or Commercial Exterior Lights and Appliances Based On The Ambient Light Level. Features Include The Coated Circuit Board and Weather-Resistant Casing, Long-Life Zero-Cross Technology and The Time Delay That Prevents Stray Lights or Shadows From Triggering The Control. Designed For Applications Including Landscape Lighting, Perimeter and Security Lighting, Pole Lanterns or Signage.