Clearly intercepts the voices of both parties when the telephone line is occupied. Operates as a normal surveillance transmitter if the handset is on the cradle. Reduced dimensions. Exceptional audio performance. Amplification control. Microphone cable length on request. A distance of more than 600 meters can be reached in an open field thanks to the power output. The performance obviously depends upon the environmental conditions and the sensitivity of the receiver utilized. To obtain maximum performance, it is advisable to utilize our receivers. Technical data: Power: Directly from your telephone line Emission frequency: UHF from 400 to 480 MHz Modulation type: WFM Dimensions: Width 30 mm, height 4 mm, length 40 mm Show More