Controls a vehicle's dome light to add a theater lighting effect, gradually turning on and gradually fading off the dome light. Monitors the door switches and switched power line to control the dome light. When a door is opened, the dome light gradually brightens to full intensity. When a door is closed, the dome light remains on for up to 20 seconds then fades off. Designed to work with vehicles that switch the dome light on and off by switching the ground side of the circuit (such as classic GM and Chrysler vehicles from the 60's and 70's). Monitors the switched power line to refine the experience. If the key is off, the dome light is held on for 20 seconds. If the key is on, the dome light fades off as soon as the door is closed. When the key is switched off, the dome light automatically turns on. Adds theater lighting to your classic car or truck. For 12V, negative ground vehicles which control the dome light by switching the ground side of the dome light circuit (classic GM and Chrysler vehicles from the 60's and 70's). 2 by 1.5 by 1 inches. Fully potted. Made in USA. Adding this module gives a theater lighting effect to your classic vehicle. Softens the interior lighting by gradually brightening the dome light when turning on and fading the dome light off. Automatically turns on the dome light when the key is switched to the off position. Will keep the dome light on for 20 seconds after a door is closed before fading off (if the key is off). If the key is on, the dome light fades off as soon as the door is opened. If a door is accidentally left open, the dome light is switched off after 15 mintues to preserve battery power. For 12V vehicles which control the dome light by switching the ground side of the dome light circuit (classic GM and Chrysler vehicles).