Product functions and features: 1 Support Bluetooth wireless transmission 2 Built-in microphones for hands-free calling 3 Using high-quality audio decoding chip, allowing you to experience perfect sound quality 4 Unique waterproof function design, can be used in the bathroom, beach, swimming pool, at the same time of leisure, enjoy relaxing and wonderful sound 5. Simple and stylish shape; easy to carry around; the chassis can be sucked on mobile phones, Apple tablets and desktops; very practical; colors meet the needs of different people. Product parameters: Color: blue+black Bluetooth Version V: 5.0 Frequency: 2.402-2.480GHz Output power: 3W Microphone sensitivity: -32db Receive sensitivity: higher than 82dBm Receiving distance: 10-15 meters Data Transfer : Greater than 3.0 Mbps/sec UART data transfer rate: 115200bps Bluetooth antenna: built-in Bluetooth antenna Charging voltage: 3.7V 4.2V DC Operating voltage: 4.8V 5.5V DC Playing time: 3 to 8 hours (depending on whether the volume is too low, the time varies) Charging time: 2-3 hours