Catalog Number: PSD0108-UNV-IV Type: Single-pole or 3-way (meaning it can control a light from one or two locations). Voltage: Universal voltage (UNV), rated for both 120VAC (10A) and 277VAC (5A). Color: Ivory (-IV at the end of the model number). Compatibility: Designed for LED and CFL lighting that supports a 0-10V dimming signal. What makes this different from a standard dimmer? Most standard home dimmers vary the voltage on the power line itself. This device, however, has extra wires to send a low-voltage (0-10V) signal to the light's driver, telling it exactly how much to dim. This provides smoother dimming and is often required for large office lighting or modern architectural LEDs. Important Safety Note: Because this device supports 277V (common in commercial buildings) and requires specific low-voltage wiring, it is highly recommended that it be installed by a qualified electrician