Specification: Bluetooth-compatible Version: 5.3 Chip Type: 5605 B Battery Type: Polymer lithium battery Battery Capacity: 400 mAh with protection board Charging Time: Approximately 2 hours Usage Time: Over 40 hours Standby Time: Approximately 200 hours Speaker: 40 mm dynamic driver Charging Port: Type-C Transmission Range: Up to 10 meters without obstacles Transmission Power: 5V1 A Noise Reduction Level: Deep noise reduction up to -25 dB Speaker Sensitivity: 1133 dB Frequency Range: 20-20,000 Hz Signal-to-Noise Ratio: 88 dB