520 Gen2 Earhook Business Bluetooth Headphone, Style: With Charging Case 1. Bluetooth version: V5.1andEDR 2. Wireless frequency: 2.4GHZ 3. Support protocol: A2DP1.3HFP1.6HSP1.2AVRCP1.6D11.3 4. Transmission distance: about 10 meters 5. Battery capacity: earphone 50mAh, charging case 400mAh 6. Charging voltagecurrent: 5V1A 7. Speaker impedance: 8mm 32Ω 8. Microphone sensitivity: -42dB 9. Weight: earphone is about 12.5g, charging compartment is about 78g Features: 1. 360-degree panoramic sound, TWS true wireless, surround stereo sound 2. Large moving coil and loud volume, no fear of noisy environment 3. ENC dual microphone noise reduction, clear call 4. CVC8.0 intelligent noise reduction core, eliminate call noise, restore high-definition human voice calls 5. Double independent adjustment shafts, soft silicone ear hooks, adjustable wearing angle 6. Memory pairing, automatic connection back 7. Multi-function button operation, simple and convenient Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.