Features Function: SD Card / FM Mode / AUX / Button Control Chip: JL6955F Bluetooth Version: V5.3 Headphone Battery: 400mAh Talk Time: 14 hours Charging Time: 2.5 hours USB Port: Type-C Headphone Dimension: 199*156*77mm Headphone Net Weight: 187g Wireless Working Range: 10M Speaker Size: 40mm