Extra-loud ringtone amplifier. Features: Up and down switches for ringtone sound. To increase the volume of the telephone ringtone in noisy places. To help the hearing impaired recognize when the ringtone is coming. Lamp flashing is offered to avoid ringing noise in quiet environment. Features: Compatible Brand: Panasonic Model Number: Phone Ring Type: Telephone Ring Hardware: Mine: Plastic size: 97mm*57cm*25mm Color: White Installation: 1. Please connect C/O Ring plug with Ringer plug. 2. The Ringer's Plug Connet with telephone. 3. There are up and down switches for your selections. Contents of the box: 1 X Ringtone.