Spy Bug Receiveris A Narrow Pulse Nanosecond Transmitting A Wireless Signal Technology Is Ideal For High-Speed,Short-Distance Wireless Personal Communications, X-990 Has A Very Strong Ability Of Anti-Multipath Interference, Especially Suitable For Indoor Complexenvironment To Ensure High Sensitivity Pickup To Provide Users With Highly Reliable Wireless Transmission Environment. Low-Power, Low-Cost, High Reliability.