Resi-TonerTM is a full function tone generator with unique features designed to further test connections on telephone systems and speaker installations. Find your outlets and assure your connections with the Resi-TonerTM "Powers-up" the installed telephone lines under actual load conditions with a simulated dial tone to check connectivity and proper wiring configurations without a service connection Full-feature tone generator with 3 different tone sounds and continuity test Generates a unique tone sequence for testing speaker installations by "popping" speakers---will work with either AC or DC coupled speaker types Requires 9V battery (not included)