Medallion™ Series products bring Silent Call benefits to people who are deaf, deaf-blind or hard of hearing. Designed with million-code technology, the receiver 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 (150 meters), depending on product combination. (Note: Normal stated coverage between the transmitter and receiver is clear line of sight. Coverage can be affected by concrete-reinforced walls, TV transmitters, computers, mobile phones and other factors).