If a telephone monitoring operation is on long term basis or access to the target area is restricted then the PKI 2210 Telephone Transmitter is the perfect solution. It is not necessary to have direct access to the telephone set. Any location along the telephone line can be used for monitoring. This Telephone Transmitter operates automatically, i.e. the internal off-hook detection circuit automatically switches from standby to activation and transmission. Only transmitting when a telephone conversation takes place, this wireless bug is undetectable. The sensitivity on the telephone line can be adjusted manually. Another advantage is its independence from short-lived power supplies like batteries, so that a continuous monitoring of the target area is guaranteed. The installation on the telephone line should be made in serial mode. Both polarities are allowed. The PKI 2210 Telephone Transmitter is available in standard UHF. Special frequencies on request.