Retractable Unique DesignThe Retractable Bluetooth Headphones body can be clipped on clothes or collars.When you need,Stretch the earbuds in-ear.When you don't need,Take out the earbuds and Press rewind button,The earbuds are retracted,Release the pressure of ear. It's Very user-friendly DesignQuick Charge, 20min=99%BatteryOur Wireless Headsets Build in 5C battery. It only takes 20Min to get almost fully charged, 20hours working time (volume 70%). 150 Hours Standby Time,Meet your daily needs.1 Drag in 2 Connect The K55 headphones with one key to power on and enter pairing mode,1 drag in 2 connect two phones. Noise Reduction boom microphone and Dynamic Speaker broadcasts your speech clearly when you move around and perform your tasks while having a phone conversation or speaking to a crowd.With 33ft (10meters) Bluetooth working range.Upgrade LED Battery DisplayFirst upgrade Retractable Bluetooth Headset Built-in LED battery capacity display. Uses sensitive Battery capacity to recognize accurate capacity , allows you to enjoy music and clear phone calls whenever ,Never worry about out of PowerBLUETOOTH HEADSET 5.2 Through Bluetooth 5.2 Wireless headset audio technology and enhanced voice clarity . That Suitable for mobile calls, streaming music, and GPS directions and so on., Voice announce the phone number of income caller,one key to answer, reject, end and redial the last number.easy and fast pairing with smart phones and tablets, compatible with iPhone, Samsung, LG, Xiaomi,OnePlus,Motorola and other Android cell phones.