ONLY WORKS FOR LANDLINES.
DOES NOT WORK WITH VOIP OR CORDLESS PHONES.
Automatically alerts you to any extension phone left off-hook throughout your home and in addition alerts you if your phone service has been interrupted
Just one unit will monitor one phone line for your entire house Requires 2 AAA batteries, not included
2 Different audible alarm tones (one for off-hook and the other tone for service interrupted)

Technical Details

Product Details

Package Dimensions
Width : 4.8 inch
Height : 2 inch
Length : 9.2 inch

Shipping Weight: 0 ounce (View shipping rates and policies)

ASIN : B01GUZHLRI