The TS19 butt-in test set has been specifically designed for the in house technician. This Back-to-basics test set has both tone and pulse operation, last number redial, solid state circuitry and a high impedance monitor. It is ergonomically shaped to be comfortable. All the features of a basic test set at a very basic price. Features: Talk/monitor/ringer modes, Tone and pulse operation, Continuous polarity indication, Last number redial: 18 digits, tone or pulse mode, Electronic ringers, On/Off, Field replaceable belt hook, High impedance monitor for datasafe operation, hearing aid compatible