Feature 1 Unlimited Receivers: Wireless monitoring system, unlimited number for S3 receivers can be used on the same frequency. 2 Frequency Band: 626 to 662MHz ear monitor system receiver, can only be used in this frequency band, with stable performance. 3 Small And Lightweight: A compact bodypack ear monitor receiver that is lightweight and easily attached to a belt or guitar strap. 4 Professional: Ear monitor return system is suitable for S3 wireless earphones, 3.5mm stereo output, giving you a better monitoring experience. 5 Multiple Applications: Wireless ear monitor system is suitable for live broadcast listening at exhibitions, stage performances, band, etc.Item Type: Wireless Ear MonitorMaterial: ABSFrequency: 626-662MHzAdjacent Channel Rejection: 70 DBIntermodulation Attenuation: 70 DBReceive Sensitivity: 20 dBuVAntenna: 1/4 Wavelength Weaved AntennaHeadphone Output Interface: 3.5mm/0.1in InterfaceStereo Jack Headphone Output Power: 100mW (32 Ohms)Maximum Current: About 190mABattery Life: 8 HoursReceiver Battery: 2 x AA Batteries (Not Included)Headphone Output Interface: 3.5mm/0.1in Stereo Jack Package List1 x Wireless Ear Monitor (Battery Not Included)1 x Headphone2 x Pairs of Ear Covers