Description: Retractable: earphone with control button can make the earphone cable retractable, easy to store and organize. Hand Free Calling: The wireless headphone can remind you with vibration. Lavalier Headset: Collar clip and flexible design, portable and easy to carry. 5.2: Adopt 5.2 technology, stable connection up to 10m, noise reduction. Battery Life: The wireless headphones, built in 140mAh battery, can continuously play the headphones up to 20 hours when charged fully. Specification: Model: K55 : 5.2 Transmission Distance: 10m Transmission Frequency: 2.4G Charging Voltage: DC 5V Charging Time: less than 20 minutes Talk Time: about 20 hours Music Time: about 20 hours Standby Time: about 180 days Battery: 140MAH Body Size: (LxWxH)56x25x13mm/2.20x0.98x0.51inch (with back clip height 20mm) Material: Plastic Package Includes: 1 Piece 5.2 Lavalier Earphone 1 Piece Manual 2 Pieces Earbuds 1 Piece Charging Cable Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful online shopping!