TP-WIRELESS TP-WMS02 In-ear Stage Audio Monitor System Professional 2.4GHz Digital Wireless Monitor System 1 Transmitter 1 Receiver Features: * 2.4GHz is an ISM frequency band which is legal and free all over the world. * Unlike UHF device's analog signal, 2.4GHz can realize digital transmission. * The sampling rate is 64K at 16bit*2, we call it HDCD sound. * Latency time: 1.1-2ms. It is the shortest latency time in this field. * The practical test S/N ratio is 89dB, and the practical test THD is 1.5%. * Support at most 6 sets using at the same time without mutual interference.    * Multiple sets of receivers can be operated with a single transmitter within the operating range. Note: AA batteries for the receiver are not included, please buy them in addition. Specification: Transmitter: Frequency Range: 2400MHz-2483MHz Power Supply: DC 5V/500mA Transmit Power: ≤20dB Operating Range: 30 meters (Open Space) Receiver: Frequency Range: 2400Mhz-2483MHz Power Supply: DC 3V (2pcs AA batteries not included) Frequency Response: 20Hz-20KHz SNR: 89dB THD: 1.5%@1KHz Earphone: Frequency Response: 20Hz-22000Hz   Impedance: 16Ω Sensitvity: 110(dB) Transmitter Size: 7.9 * 7.0 * 2.4cm / 3.11 * 2.75 * 0.94in Transmitter Weight: 143g / 5.04oz Receiver Size: 10.0 * 6.6 * 2.5cm / 3.93 * 2.59 * 0.98in Receiver Weight: 96g / 3.38oz Packing List: 1 * Transmitter 1 * Receiver 1 * Earphone 2 * Pairs of Earcap 1 * 3.5mm Audio Cable 1 * 3.5mm to 6.35mm Connector 1 * 3.5mm to RCA Stereo Cable 2 * Antenna 1 * 5V 500mA Power Adaptor 1 * English User Manual