The Radio Hailer wireless PA speaker is the ideal solution where a hard-wired PA installation is simply impossible, too expensive, or temporary needed. The Radio Hailer allows you to use your portable 2-way radio, base station or mobile radio to deliver live voice messages directly to a PA speaker up to 1 mile away. Multiple units can be placed throughout a facility, programmed identically, and activated simultaneously as a group. Lets you communicate information and alerts from a distance of one mile or more. Use your own 2-way radios or AmpliVox 2 Watt MURS frequency transceivers (does not require FCC licensing). Two handhelds are required: one acts as the receiver, the other as the transmitter. Great "grab and go" addition to safety and training teams.