UHF (ultra high frequency) wireless monitoring system is especially designed for instrument/ stage monitoring and simultaneous interpretation. It supports up to 10 channels and is suitable for multilingual interpretation. With 164ft long transmission distance and stable performance, it's very practical to use. Features: A wireless monitoring system tailored for instrument/ stage monitoring and simultaneous interpretation. LED digital display for easy reading and convenient use. 520-600MHz UHF wireless transmission, 50m (164ft) transmission distance without obstacles, PLL (phase-locked loop) technology, stable and reliable performance. Anti-interference composite circuit is designed for using multiple bodypack receivers simultaneously. Supports up to 10 transmitters working at the same time, suitable for multilingual   interpretation. (Note: only a receiver and a transmitter are included.) Dynamic companding circuit with high S/N ratio (>60dB) for clear audio output. 3.5mm audio input on transmitter, easier to connect with mixer, amplifier or other audio device. Includes in-ear earphones (3 pairs of ear tips in total -- S/ M/ L, the L ones are assembled) that are comfortable to wear and offer rich delicate sound and strong bass. Note: Size and color may be slightly different due to manual measurement and different light conditions. Thanks for understanding. Specifications: Plug: EU/ US (Optional) Color: Black Material: Plastic Package Size: 27 * 22 * 6.5cm / 10.63 * 8.66 * 2.56in Package Weight: 551g / 19.42oz Transmitter: Operating Frequency: 520-600MHz Operating Current: 100mA (TYP) Power Supply: DC 12V/300mA Transmitting Distance: ≥50m/ 164ft (open area without obstacles) Transmitting Power: 5dbm (TYP) Size: 159 * 60 * 22mm / 6.26 * 2.36 * 0.87in Weight: 118g / 4.17oz Receiver: Frequency Range: 520-600MHz Operating Voltage: DC 2.5V (2.2V-3.0V)/ 2 AA Batteries (not included) Operating Current: 115mA (TYP) Frequency Response: 20Hz-15KHz (-6dB intercept point) S/N Ratio: >60dB Receiving Sensitivity: better than 8dbuv Stereo Separation: >45dB Size (without battery): 90 * 64 * 25mm / 3.54 * 2.52 * 0.98in Weight: 76g / 2.69oz Package List: 1 * Transmitter 1 * Bodypack Receiver 1 * In-ear Earphone (a pair of ear tips are assembled already) 2 Pairs of Ear Tips (spare) 1 * 3.5mm Audio Cable 1 * RCA Audio Cable 1 * 3.5mm to 6.3mm Plug 1 * Power Adapter 1 * User Manual (English)