Description: 【Advanced Chip Design】: This cordless microphone system features a high-integration chip design with ID code pairing certification, ensuring reliable and stable performance for your audio needs 【Versatile Channel Options】: With 30 adjustable channels, you can easily find the best frequency to avoid interference and ensure clear sound transmission 【Wide Frequency Response & Stability】: Enjoy a broad frequency response range of 40Hz-20kHz and frequency stability of ±3PPM, delivering audio output for various applications 【Long Operating Range & Battery Life】: The device operates effectively within a range of 50-80 meters and is powered by a built-in 3.7V, 500mAh lithium battery that provides up to 6-8 hours of continuous use on a single charge 【Universal Compatibility】: Designed for use with speakers, amplifiers, mixers, or guitars, this product comes with essential accessories Specification: Material: PP Channels: 30 Modulation mode: DOPSK Frequency stability: ±3PPM Frequency Range: 40Hz-20KHZ Working range: 50-80M Working voltage: 3.7V Size Chart: 11cm/4.33inch Package Includes: Packaging options: 78028841 2pcs:  1 receiver 1 transmitter 2 converter heads 1 USB Cable 78028842 3pcs:  1 receiver 2 transmitter 2 converter heads 1 USB Cable Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.