Characteristics and Interoperability Clear and flawless are the original horn, high, medium, and low frequencies. Integrated microphone for crystal-clear calls Features of the product: Clear and flawless are the original horn, high, medium, and low frequencies. Integrated microphone for crystal-clear calls Intelligent touch: it has the ability to turn on and off, mute music, answer the phone, and change the volume. Product specifications: Version of Bluetooth: 5.3 Range of operation: 10M Response frequency: 20 Hz–2 kHz Impedance: 32 Ω The DC 5V charging voltage The earphone can be fully charged three times when the charging chamber is fully charged. Battery capacity: 3.7V, 300mAh; charging time: approximately 2.5 hours. Earphone service life: approximately 3–4 hours; battery capacity: 3.7V, 40mAh; charging time: approximately 1.5 hours (10–12 hours with charging compartment) Pairing process: Upon removing the earphone