VTech Telezapper Model 2551

Excellent unit. Filters out 99% of telemarketers.Political telemarketers slip through due to federal law governing same. My unit came with two extensions which work great in a 3500 square ft. two story house. I can even carry the downstairs extensions into the yards and have good reception out to about 100 feet. I have a non -Vtech add on for a shop phone and it integrates with this unit with no problems. Formerly carried by Wal-Mart but now obtainable on-line from numerous sources using Google search. Price seems to hover around $60. Do not confuse this unit with a $19.95 plug in device sold elsewhere using same name. This is a full fledged system that includes caller id along with the tele-zapper feature. Previous reviewer must have bought a bad unit.