The Electronic 24Hr 120 VAC Replacement Clock Kit for Mechanical PB Clock These compact Electronic Timers are specially suited for applications where equipment needs to be cycled ON and OFF up to 8 times per day, and where automatic operation of the equipment requires occasional override by someone other than a qualified service professional. They offer rugged construction, resistance to surges and humidity, operate between wide temperature extremes and come with a 5 year service life replaceable lithium battery. A light indicator illuminates when the timer is in the ON position. Select feature allows timers to be continuously ON, OFF or in AUTO mode. PB300EK Series Electronic Timer kits are designed for applications where PB Series Mechanical Timers need to be replaced. The connected load must not exceed the ratings of these timers. The kits contain all the necessary hardware for a speedy repair or exchange.