1-to-4 UHF Portable Wireless Transmitter Receiver Clip Lapel Headset Microphone(642.2-660.8Mhz) This product adds several new domestic unique technologies based on the original microphone technology, which makes the system have ultra-high sensitivity, strong anti-interference ability and excellent stability. The original technology includes high-efficiency low-cost RF emission technology and SMT production process in the United States, and uses a locking frequency of better than 10ppm quartz crystal, dynamic audio compression, expansion circuit, image frequency suppression circuit, switch-time shock elimination circuit, anti-return circuit Variable output control technology, computer EDA, analog online assisted design, etc. Features: 1. The frequency is fixed, it can be used at boot, convenient. 2. Four-channel volume is independently adjustable, providing 1+4 audio output, and four-channel audio output is independently controllable. 3. Handheld/collar clips in the transmitter can be used in a mix and match. 4. 5 sets of different frequency points can be used simultaneously. 5. Very suitable for stage performance. 6. Lightweight, mini size. Easy to carry. Specification: Model: U-F4000 Weight: about 896g/31.61oz (transmitter), about 270g/9.52oz (receiver*4) Size: about 48*19*4cm/18.9*7.48*1.57in (transmitter), about 11*6.3*2cm/4.33*2.48*0.79in (receiver) Battery: AAA*2 (Not Included) Transmit power: <30mW (depending on applicable national regulations) Harmonic power: <40dB (main wave) Battery life: >10 hours Oscillation mode: quartz crystal oscillation Stability: 10PPM Wireless interface: BNC/50Ω Maximum frequency offset: 50KHz Signal to noise ratio: >105dB Distortion: <0.5%@1KHz Image interference: >85dB Adjacent frequency interference: >75dB Frequency response range: 60Hz~16KHz Squelch control mode: multiple squelch circuit Maximum output level: +10dBV Sensitivity adjustment range: 12-32 dBμV Power supply: external DC power supply, 0.8A, 12~15V DC Use distance: Open environment: 50-80m Complex environment: 30-40m Frequency range: 621.5~643.7Mhz Package List: 1 * Transmitter 4 * Receiver 1 * Instruction Manual 4 * Microphone 1 * Charger 1 * Audio Cable 2 * Antenna