UHF wireless receiver is designed for instrument/ stage monitoring and simultaneous interpretation. With reliable and stable performance, it's very practical to use. Features: 520-600MHz UHF (ultra high frequency) wireless transmission, stable and reliable performance. LED digital display for easy reading and convenient use. Attached back clamp for easy use and carry. Anti-interference composite circuit is designed for using multiple bodypack receivers simultaneously. (Note: only 1 receiver is included.) 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. Combined with transmitter (not included) for instrument/ stage monitoring and simultaneous interpretation. Note: Size and color may be slightly different due to manual measurement and different light conditions. Thanks for understanding. Specifications: Color: Black Material: Plastic 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 Item Size (without battery): 90 * 64 * 25mm / 3.54 * 2.52 * 0.98in Item Weight: 76g / 2.69oz Package Size: 25.1 * 13.2 * 4.5cm / 9.88 * 5.20 * 1.77in Package Weight: 125g / 4.41oz Package List: 1 * Bodypack Receiver 1 * In-ear Earphone (a pair of ear tips are assembled already) 2 Pairs of Ear Tips (spare)