Clearsounds In-Line Amplifier IL40 $31.95 Description: Attaches to corded phones to increase incoming volume of phone call up to 40 dB. Adjustable tone control allows to shape sound to meet hearing needs. Compatible with 99% of telephones. Compact size designed for portability. Connects to corded phones with dial pad in base. Not for cordless or trimline phones. Dimensions: 3-7/8w x 2-1/2h x 1-1/3d. 1 year warranty.