Instructions: Shut down: long press the middle button for three seconds until the red and blue lights double flash Language switch: Double-click the middle button to switch between Chinese and EnglishFeatures: Easy to Operate: Simply connect your speaker/headset with our device, immediately transform your speaker/headset into a fashionable wireless Bluetooth speaker/headset. Wireless Play: Removing troubles of a wired connection, through the wireless connection and transmission, the user can enjoy a high fidelity music at any place indoor by wireless control. Portable Design: Mini size with clip design the feature of the portable can let you carry them to anywhere you want. Support for iPhone, Android phone, other smart phones which with Bluetooth A2DP function. Compatible with home stereos/speaker, car stereos, headphones that is with 3.5mm audio input. Specification: Type: Bluetooth Audio Receiver Material: Plastic Quantity: 1 pc Item Color: Black Bluetooth Version: 4.1 Frequency Range: 2.4GHz Profile: A2DP Transmission Range: Up to 10m / 33ft I/O 3.5mm female plug, Mini USB female port Power Supply: DC 5V Charge Time: About 30 min Working Time: About 4h Size: 1.4*1.5*5.8cm / 0.5*0.6*2.3" (L*W*H) Package: 1*Bluetooth audio receiver 1*3.5mm to 3.5mm adapter 1*English user manual