Greenlee PE620 Alarm Loop Verifier/Tone Generator In the latching mode, the unit will catch the alarm condition and continue sounding until the tester is reset As a tone generator, the unit provides a traditional variable tone that can be applied using the 24" red and black test leads or a convenient 6-position modular plug Convenient magnetic back plate allows the PE620 to be mounted directly to the control panel cabinet or door Battery operated, 9V battery not included Uses 9 Volt Battery