Features:-It adopts a lightweight in-ear design and comes with earplugs of different sizes to ensure a tight fit, comfortable wearing and reduced howling.-The left ear is blue and the right ear is red, making it easy to tell which ear it applies to. With obvious on/off button for easy operation.-Hidden design, looks like a Bluetooth headset, so you won't feel uncomfortable.-Equipped with a 300mAh large-capacity charging box, it can be fully charged in about 30 minutes and can be used for about 6 hours. The charging box can provide 5 charges when fully charged.-Built-in intelligent digital chip, intelligent noise reduction, no fear of noisy environment, providing excellent sound quality.Specification:Maximum sound output: 118+/- 3dBSound gain: >= 35dB+.