
Viking 15 Watt Paging and Amplifier Loud Ringer (PA-15)
600 ohm output to drive additional amplifiers

Algo 1825PM Duet Plus Analog Ringer Loud & Paging Amplifier
Interfaces easily with optional Algo 1186 Horn Speaker to provide increased ringing or voice notification volume (up to 112 dBA SPL at 1m (3.3ft.))

Telephone Ringer Amplifier Connected by Essentials
COMPACT DESIGN - Dimensions 3.1x2.4x0.98in (80x60x25mm)

Sscon Telephone Ringer Amplifier Socket Lound Ring Telephone Speaker for Landline Telephone
Package Includes: 1 x Telephone Ringer Amplifier

RadioShack Radio Shack Ringer Mechanical Amplifier
Pulls enough power from the phone line to provide a 65-75 dB ring.

Viking PA-2A Paging
The unit comes complete with a power supply, amplifier, and (1) Viking 25AE paging horn

discoGoods 2 Pack Socket Loud Telephone Ring Speaker Bell Ringer and Amplifier Ringtone 95db Volume Enhancer for Landline Telephone With Flashing Light
On and off switch on the side of the ringer. Easy to control of the ringer sound.

Woods Telephone Bell Amplifier Ringer Unit
Perfect for the garage, patio, workshop, basement, laundry room

Woods Telephone Bell Amplifier Ringer 0934
Easy to install

Funien Loud Sound
Need another adapter for UK buyers or others.