Features:Power supply: DC 5V (Micro USB interface)Audio input: various versions bluetooth connection stereo input, using CSR64215 bluetooth chip, bluetooth V4.2, support low delay, high software compatibilityAudio output:1. 3.5mm headphone stereo audio output (dedicated amp chip processing can directly drive the headphones or to the amplifier audio input)2. RCA audio stereo audio output (for audio amplifier input, can not drive headphones)Shell material: aluminum anode goldNote:The red one is available now, will send the color randomly.Package included:5 x HIFI-Class bluetooth 4.2 Audio Receiver Amplifier