Características especiales Portable Design: Mini size with clip design the feature of portable can let you carry them to anywhere you want, Built-in rechargeable lithium battery, provides up to 4 hours working time, plug and play, and only takes 50 minutes to fully charge, BLUETOOTH 4.1 PORTABLE RECEIVER:Built with Bluetooth 4.1/HFP/HSP/A2DP/AVRCP to smart your life that you can enjoy music and hands-free calling from your smartphone in premium-quality sound.Up to 33ft connection range guarantees low signal delay.Our Bluetooth Car Adapter is not only for car, it is also could connect with your wired headphones via 3.5mm audio cable/adapter to help you enjoy the wireless., DOUBLE LINKS WIDE COMPATIBILITY: This Mini Bluetooth Receiver can connect two Bluetooth devices at the same time.It also could compatible with most smartphones and Bluetooth electronics, best ideal for home or vehicle audio systems and wired headphones.Please do not attempt to connect the gadget to such as Bluetooth headphones or speakers, this is meaningless since the functions as a Bluetooth receiver for those devices without Bluetooth feature itself but desire to receive Bluetooth signal.