The Φ52mm High-Fidelity Speaker Delivers Clean Clear Treble, Powerful Deep Bass, and Immersive 3D Spatial Audio. BT 5.1 Technology For Instant Connection, Stable & Low-Latency Transmission, High Anti-Interference Capability, And Auto Reconnection. Choose A Favorite Light Effect & Color To Go With Your Music At Night. Built-In HD Microphone Makes Your Call Hands-Free & Crystal Clear Like Talking Face To Face. With Mini-Sized Body And Lanyard Design, It Can Accompany You To Go Hiking, Climbing Mountains, And More.