Loudest and clearest in-line amplifier. Connect between the handset and the base of the phone. Amplifies up to 30 dB with the slide volume control. Hit the BOOST button for extra amplification (up to 40 dB) while blocking out feedback. Tone selector ensures every word comes across loud and clear. Easy to install, portable so you can take it with you. Note: To use the BOOST button to get the 40 dB amplification, you must hold the button down while the other person is talking and let it up when you are talking.
Note:Inline amplifiers will not work on cordless phones or phones with the dial in the handset.