Wireless Bluetooth HiFi sound quality; 2.4G dedicated omnidirectional antenna design, wireless smission range up to 65 feet; Wide range of compatibility, applicable to a of audio equipment with bluetooth stereo audio functionality; Enhanced output drive capability, the output signal is applied to the audio speakers, amplifiers, and ordinary headphones; Efficient built-in lithium battery, long battery life up to 20 hours; color: gray Material: ABS HiFi sound quality, support AAC, MP3, decoding; 3.5mm earphone output, compatible with 2RCA output for amplifier; Specifications: Bluetooth version: V4.0, CSR8635 chip Bluetooth Profile: A2DP Carrier frequency: 2.4G band Work Channel: 79 Headphone frequency response: 20Hz- 20KHz Duration: 12 hours Standby time: 330 hours Charging time: 2 hours Package Contents: 1 x Bluetooth Receiver 1 x Adapter 1 x Data Cable Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.