Plantronics HA-40 Portable InLine Amplifier for Telephone
The Plantronics HA-40 Portable Inline Amplifier allows you to increase volume and adjust tone on your existing phone. Simply connects between the hand piece and base of the phone. This is an ideal solution for home or office and is compatible with analogue and digital phones. (Please note this amplifier is not compatible with most Telstra branded analogue touch phones).