Wireless Earphone Monitor System 830‑866MHz 3 Modes Ear Return System for Guitar and Bass Player 110‑240V                                          Feature:       1. Clear Sound: Reliable RF connection coverage up to 100m/328.1ft. Up to 90 dB signal to noise ratio provides clear, complete sound at any volume. 2. Simple and Durable: There are no complicated menus, just simple buttons for volume and mix controls. Transmitter and receiver are all metal cases, strong and durable. 3. Unlimited Receving Numbers: The number of S3 receivers available at the same frequency is unlimited. Stable performance and high sensitivity. 4. Compact Size and Modes: The compact Fanny pack receiver is easy to strap onto a belt or guitar belt. Three reception modes: mix, stereo, mono.       5. Maximium 8 Systems: Up to eight wireless listening systems can be used simultaneously in each frequency band.                                   Specification:       Item Type: Wireless Earphone Monitor System Material: Iron Shell Frequency Range: 830-866mhz Earphone Output Interface :3.5mm Stereo Socket Transmitter Power: DC9v/500mA Receiver Operating Time: More Than 12 Hours Receiver Batteries: 2 x AA Batteries (Not Included) Operating Range: 100m(Open Environment Without Shelter) RF Transmission Power: <10nW Dynamic Range: 90db Harmonic Distortion: <1%(1KHz,±20KHz Frequency Offset) Frequency Response: 40Hz-18KHz Headset Output Power: 65m(32 Ohms) Voltage: 110-240V                     Package List:       1 x S3 Transmitter       1 x S3 Receiver       1 x Power Adapter       1 x Description       1 x Antenna       2 Pairs x Ear       1 x Headset       1 x Battery Compartment                                   How to use:       1. Send instrument and microphone signal (stage guitar/bass/drum/microphone voice signal) from stage to mixer or PA system.        2. Connect the mixer output port to the S3 transmitter input port.        3. Set S3 receiver and S3 transmitter to the same frequency, so that the receiver can receive the signal from the transmitter.       4. Each performer can use S3 receiver to monitor corresponding sound.