Feature 1High Quality Material: The transmitter and receiver are all metal shells, which are sturdy and durable to ensure a long service life. 2Unlimited Use: The monitoring system can use unlimited number of S3 receivers under the same frequency. 3Portable: The compact body pack receiver is easy to be tied to a belt or guitar strap, which is light and practical without burden. 4Easy to Use: No complicated menus, only simple volume and mixing control buttons, three receiving modes: mixing, stereo, and mono. 5Clear: The signal to noise ratio of up to 90 dB can provide clear and complete sound at any volume, reliable radio frequency connection coverage up to 100m.Item Type:Wireless Earbud Monitor SystemMaterial: Iron ShellFrequency Range: 626-662MHzHeadphone Output Interface: 3.5mm Stereo JackTransmitter Power Supply: DC9V/500mAReceiver Working Time: More Than 12 HoursReceiver Battery: 2 x AA Batteries (Not Included)Operating Range: 100m (Open Environment without Obstruction)RF Transmit Power: <10nWDynamic Range: 90dBHarmonic Distortion: <1% (1KHz, 20KHz Frequency Deviation)Frequency Response: 40Hz-18KHzHeadphone Output Power: 65m (32 Ohm)Voltage: 110-240V .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List1 x S3 Transmitter1 x S3 Receiver1 x Power Adapter1 x Manual1 x Antenna2 Pairs x Ear Caps1 x Headphone1 x Battery BoxNoteEach frequency band can use up to 8 sets of wireless monitoring systems at the same time.