Byikun Wireless Earbuds Bluetooth Headphones, Comfortable Children's Headphones, Noise Cancelling Headphones for Kids, Ear Buds Wireless Bluetooth Earbuds, Earbud & in-Ear Headphones

? Specifications: ?     BT Version: BT5.3 ?     Transmitting Distance: 10m/33ft ?     BT Protocol: HFP, A2DP, HSP, AVCRP ?     Frequency Range: 20-20000Hz ?     Sensitivity: 103dB ?     Impedance: 16O ?     Waterproof: IPX5 ?     Charging Box Capacity: 3.7V 200mAh ?     Earphone Battery Capacity: 2 x 3.7V 40mAh ?     Music Play Time: about 4 hours (depends on music volume) ?     Charging Time: about 1.5 hours for earphones, 2 hours for charging box ? Package Include: ?     2x Mini Earphones (Left and Right Ear-buds) ?     1x Charging box ?     1 x USB Cable