The Universal Phone Amplifier converts any corded telephone into an amplified phone. It connects between the handset and the phone base with up to 45dB amplification (200 times louder) and Tone Control, you can now hear clearly on your existing home phone.
The Amplifier accessory VZ4 C21 for Bosch T9 models Volume and tone control is an amplifier accessory that pluggs in between the handset cord and the device using a Western-Plug connection and are thus already installed.
Clarity® Telephone handset amplifier features adjustable incoming volume control/Clarity® Power™ technology for louder/clearer sound. Amplifier enhances incoming sounds up to 40 dB and is ideal for analog/digital corded phones.