Features: Uses a VHF 240 MHz~270 MHz PLL frequency synthesizer technology Uses a multi-channel high band and intermediate band frequency selective filtering, in order to fully eliminate interference signals. Built-in feedback eliminating technology can effectively decrease the feedback and noise. A built-in multiple noise detecting circuit and TONE-LOCK system make sure the system has a strong anti-jamming function. Perfect performance with the best chips and components, it uses an SMD original mount design to enhance the product quality and stability The operation distance reaches up to 60 meters with the best conditions, and 40 meters under normal conditions The frequency and channel are locked to protect the anti-jamming functions