OverviewMaterial: ABS + PC, Frequency Response Range: 20 - 20000Hz, Bluetooth Version: 5.0, Effective Distance: 10 meters, Protocols: A2DP, AVRCP, HFP, HSP, Autonomy In Playback Mode: Up to 4 Hours, Usage Time with Charging Box: Up to 30 hours, Headphone Charging Time: 2 Hours, Single Earbud Battery Capacity: 55mAh, Charge Case Capacity: 600mAh, Battery Type: Polymer Lithium Battery