Single Channel Transmitter:
• Frequency: 470-960 MHz
• Frequency quantity: 40
• Transmitter power: 3 level adjustment: 20dBm, 17dBm, 10dBm
• Audio Input gain: 2 level adjustment
• Audio Input type: USB, XLR/48V, RCA
• Frequency response: 50Hz - 15kHz (±3dB)
• Power dissipation: DC12V / Max.:250mA (±10mA)
• Working temperature: -10°C - 40°C
• Antenna Port: BNC
• Antenna Impedance: 50 ohms

Single Channel Receiver:
• Frequency: 470-960 MHz
• Frequency quantity: 40
• Receiver Sensitivity: < -96dBm
• Frequency response: 50Hz - 15kHz (±3dB)
• Power dissipation: 3V / 80mA (±10mA)
• Working temperature: -10°C - 40°C
• Battery: 2 x 1.5V AA battery

Double Channel Transmitter:
• Frequency: 500-950 MHz
• Frequency quantity: 40
• Transmitter power: 100mW
• Audio Input port: XLR, *6.3mm double
• Frequency response: 50Hz - 15kHz (±3dB)
• Power dissipation: DC12V / 600mA 
• Working temperature: -10°C - 40°C
• Antenna Port: TNC
• Oscillation mode: PLL

Double Channel Receiver:
• Frequency: 500-950 MHz
• Frequency quantity: 40
• Receiver Sensitivity: < -96dBm
• Frequency response: 50Hz - 15kHz (±3dB)
• Power dissipation: 3V / 80mA (±10mA)
• Working temperature: -10°C - 40°C
• Battery: 2 x 1.5V AA battery
• Earphone output port: *3.5mm
• Earphone output power: RL = 32 ohms, 30mW

The main components of a wireless in-ear monitor system typically include:

Transmitter: 
The transmitter is the central unit that connects to the audio source, such as the main mixer or monitor console. It converts the audio signals into a wireless format and broadcasts them to the individual receivers worn by the performers.

Bodypack Receiver: 
Each performer wears a bodypack receiver, which receives the wireless audio signal from the transmitter. The bodypack receiver is typically compact and can be attached to a belt or pocket. It has a headphone output where the performer plugs in their earphones or in-ear monitors.

Earphones or In-Ear Monitors: 
These are the earpieces that the performers wear in their ears to listen to the audio feed from the bodypack receiver. In-ear monitors come in various styles and configurations, including custom-molded options for a comfortable and secure fit.

Antennas: 
The transmitter and receivers have antennas for wireless communication. The type of antennas can vary, and some systems may have diversity antennas for better signal reception and to minimize dropouts.

Power Supplies: 
Both the transmitter and receivers require power to operate. They are typically powered by rechargeable batteries or disposable batteries.

Advantages of using a wireless in-ear monitor system:
Personalized Monitoring: Each performer can have their own mix, adjusting the levels of various instruments and vocals to suit their preferences, enhancing their overall performance experience.

Reduced Stage Volume: In-ear monitors reduce the need for traditional floor monitors, decreasing the on-stage volume and improving overall sound clarity for both performers and the audience.

Mobility: 
Performers are not tied to a specific location on stage, as they would be with floor monitors. They can move freely while still having consistent audio monitoring.

Isolation:
In-ear monitors provide better isolation from external sounds, allowing performers to focus on their own mix without being influenced by ambient noise.

Feedback Reduction: With proper setup, in-ear monitors can help reduce the risk of feedback, which is common with traditional floor monitors.

Aifa Pro PMS220
Wireless In-Ear Monitor System |  2-Channel Transmitter / 2-Channel Receiver