RF Wireless white Signal Repeater Booster Learning Code Extender for Call Button,Repeater Booster Learning Code Extender for Call Button RF Wireless white Signal, Just install the repeater between transmitter and receiver, while it receives wireless signal, it enhances and send out again to the receiver,This is RF wireless repeater which amplifies the wireless signal when the distance between transmitter and receiver is too long.Call Button RF Wireless white Signal Repeater Booster Learning Code Extender for.