Specifications: Model: BTH-258 BT Version: BT 5.0 Transmission Distance: about 10 meters (no obstacle) Charging Case Capacity: 3.7V 300mAh Earphone Battery Capacity: 3.7V 40mAh Color: Black Package Size: 13.3*10.2*4.8cm/5.2*4.0*1.9in Package Weight: 113g/4.0oz