The RT-100 Programmable Countdown Time Switch automatically turns lighting or other loads off when the programmed on-time expires. It replaces standard single-pole wall switches for energy savings inside and outside. Programmable countdown time switch. Replaces single-pole switch. Adjustable on-time from 5 minutes to 12 hours. Optional audible beep and/or visible light flash warnings before automatic off. Lighted switch for visibility in darkened rooms. Low-profile styling. Choice of five decorator colors. Operates most common types of lighting. Relay-based switching. Zero crossing reduces stress on the relay and increases product longevity. No current leakage to load in off mode for safety. Compatible with decorator wall plates.