Powered by SLC loop directly, no external power required. • Base mounts on standard junction boxes (4.0″/10.16 cm square by 2.125″/5.398 cm deep). • Integral LED blinks to indicate normal condition. Illuminates steady when short circuit condition is detected. • High noise (EMF/RFI) immunity. • Wide viewing angle of LED. • SEMS screws with clamping plates for ease of wiring. • Opens SLC loop automatically on detection of short, preventing the short from causing failure of the entire loop. • Automatically resets on correction of short. • Supports Style 4, 6, or 7 wiring.