Wireless Headphones AP28 HIFISOUND Black New Unopened Bluetooth I purchased these previously, but they are unopened and unused. Product Name: Wireless Earphones Model Number: AP28 Color: Black Manufacturer: SHENZHEN SHENGXI TECHNOLOGY CO., LTD. Rated Voltage: 3.7V Version: V5.3 Charging Time: Within 1 hour Working Range: 10 meters barrier-free Talk Time: Approximately 4 hours (at 80% volume) Battery Case Capacity: 3.7 / 220mAh Earphone Built-in Battery: 3.7 / 30mAh 1. The charging case needs to have sufficient power. If the earphones do not turn on when you open the cover, please put the earphones into the charging case. Close the lid and charge for at least 1 hour to power them on. 2. Do not close the charging case cover when connecting. 3. The mobile phone's Bluetooth function needs to be turned on beforehand.