Product description: Innovative design, fashionable light. Providing clear, high-quality music, you can fully immerse yourself in the world of music. Product specifications Product model: K7 BLUETOOTH version: V5.0 BLUETOOTH Communication distance: 10m Standby time: 120 hours Talk time: 4 hours Music playback: Approximately 5 hours Battery type: Polymer Lithium Battery Charging case Battery capacity: 50mAh compatible BLUETOOTH Profile: HFP / HSP / AVRCP / A2DP Allowable operating temperature: -20 ℃ -60 ℃ Weight: 45g Compatible models: iOS / Android / Windows (compatible with bluetooth 4.2 or higher) If pairing of the device and earphone fails, the following instructions Follow to reset them to factory settings. 1. First, delete the registration information of this unit from the BLUETOOTH setting on the device side. 2. Put both earphones in the charging case, and then try pairing again from the beginning. After a while, L and R are connected, and one earphone blinks red and blue alternately and quickly. One earphone turns off. 3. Turn on the function from the Bluetooth setting screen of the connected device. From the Bluetooth settings screen, tap the device name. "Connected" is displayed for the selected device name. If you have any questions or suggestions about this earphone, please feel free to contact us. We will reply to your email within 24 hours.