. Bluetooth v5.2 Wireless Earphone Hybrid Diaphragm Φ13 mm Speaker Unit Wireless Transmission Independently Half-in-Ear ErgoFit Style Transparent Case Cover Water Resistant IPX4 Automatic Connects Voice Assistant Support Extended Playtime 20H + Speed Charge USB Type-C Rechargeable Frequency Response 20 Hz - 20 kHz Earphone Sensitivity 102 dB @ -10 dB Mic. Sensitivity -42 dB @1 kHz Earphone Impedance 32 ohm Operation Distance 10 m Earphone Battery Type Lithium Battery (40 mAh) Charging Case Battery Type Lithium Battery (380 mAh) Charging Power 5V=500mA Earphone Charging Time ＜1.5H Case Charging Time ＜1.5H Music Playtime with Single Charge ≈5H Weight 39 g