The RE317D-310 is a type of ETI Polam timer relay. It is used for time-controlled switching in automation and control systems, such as lights, heater, motors and pumps. It is a simple, cost-effective digital multi-function timer with a wide variety of adjustable features to make it compatible with most applications. It features 7-day programmable functions, adjustable timing ranges, LED indicators, multiple input and output contacts, and superior protection from temperature and humidity. The unit is also designed to optimize system performance with energy saving features, such as Delay ON, ON-Delay, cycle ON, and OFF delay.