This is the Watt Stopper C120E power pack for occupancy sensors. In simple terms, it's the brain that works with compatible motion sensors to automatically turn lights on and off based on whether a room is occupied. It runs on standard 120VAC/60Hz power. It has two relays inside, which means it can control two separate lighting circuits. It can handle a 20A ballast load (for fluorescent lights), a 13A tungsten load (for incandescent bulbs), or a 1 HP motor load. The silver housing is designed for easy installation in electrical boxes. This is a professional-grade component for automating lights in offices, warehouses, hallways, or bathrooms to save energy. If you're setting up an occupancy sensing system, this power pack is a key piece you'll need. Make sure it's compatible with your specific Watt Stopper sensors.