Specifications: The left and right earphones are equipped with key for music control and telephone connection. Earphones support hands-free call and the built-in microphone can ensure clear conversation. The charging box allows you to carry earphones anywhere. Item Name: Wireless Earphones Bluetooth Version: 4.2 Power Input: DC 5V Earphones Battery Capacity: Built-in 3.7V 50mAh (Included) Charging Box Charging Time: about 2 H Call Time: about 5 H Transmission Distance: 10 Meters Call/Play Time: about 5 H Earphones Charging Time: 60 Minutes Charge Box Battery Capacity: Built-in 3.7V 350mAh (Included) Support Agreement: HSP/HFP/A2DP/AVRCP Sensitivity: 120 >< 5dB Frequency Response Range: 20 - 20000Hz Impedance: 16 Features: Wireless, Stereo, Comfortable to Wear Charging Box Size: 7cm x 5cm x 4cm/2.76" x 1.97" x 1.57" (Approx.) Notes: Due to the light and screen setting difference, the item&#39;s color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 Pair of Wireless Earphones 1 x Charging Box 1 x Charging Cable 1 Pair of Earmuff