Application： Audio Sources: fully compatible with Bluetooth-enabled audio equipment Tablet PCs notebook computers system. Output: Active Speaker amplifier headphones and other audio playback devices with 3.5mm or RCA audio input port. Supprt apyx: Bluetooth stand and protocol Bluetooth 4.0+EDR The basic Bluetooth profiles: A2DP Audio CODEC: AAC SBC aptx Operating Channels: 79 Headphone Frequency Response: 20Hz-20KHz L/R channel isolation: -82dB Maximum output power: 50mW @ 160hm load Operating voltage @ Play Current: 3.7V @ 20mA Duration: 20 hours Charging time: 2 hours