Connects between handset and base

An amplifier/sound enhancer that connects between the telephone base and the handset
Gray device that connects to phone with control buttons on bottom edge.

Audio amplifier for telephones that also allows users to connect headphones to phones that do not have built-in headphone jacks.

Amplifier with boost dial, 4 option tone switch, & 8 option compatibility switch.

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.

Black amplifier device with moving volume control and 3 buttons
This product has been discontinued.

Phone amplifier device to assist people with hearing difficulties.

A white rectangular box, shows model number top on the box and company logo down on the box

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. 

Small, square device connect to a landline telephone
This product has been discontinued and is no longer supported and serviced.

An in-line amplifier to boost the volume of your telephone calls with an easy-to-use, rotary volume control dial.