High Impedance monitor for monitoring a telephone line without disrupting existing traffic. Tone and pulse dialing for versatility on old and new phone lines
Brand name (s) : Tempo Communications

Features
Luminescent (glow-in-the-dark) keypad
Can be used safely on a DSL enabled line
High Impedance Monitor for monitoring line without disrupting existing traffic
Over voltage and over current protection
Tone and Pulse dialing for versatility on old and new phone lines
Polarity test with LED indicator
32 digit last number redial and pause
10 number speed dial
Adjustable volume control plus mute
Pause
Flash to generate a timed break recall
Line powered, no battery needed
Headset (included) for hands free operation
RJ11 socket