Silent Call Medallion Series Alerting System Designed with million-code technology, the 418MHz Medallion™ Series receivers and transmitters offer broad coverage without interference from other systems - making them ideal for use in apartments, condominiums, hotels and dormitories as well as homes. They offer extended-range, wireless convenience of up to 500 feet, depending on product combination. Five year warranty. Mini Receiver For use only with the Medallion Series, the Mini Receiver works with all Medallion transmitters and plugs into any standard 110V electrical outlet. A three level strobe - bright, brighter, brightest - will alert you to the specific activity triggering the strobe and will identify the specific event with one of 6 lighted and colored icons. It can also activate the optional bedshaker, VIB-PJ. Includes a battery back up.