Characteristics and Interoperability With original speakers, the high, medium, and low frequencies of the CA-5 High Quality TWS wireless Bluetooth earphones are crystal clear and flawless. Integrated tiny microphone for crystal-clear calls Features of the product: When using the original speakers, the low, medium, and high frequencies are flawlessly clear. Integrated tiny microphone for crystal-clear calls Intelligent touch: adjust music volume, take calls, halt video, turn on and off, Product specifications: Version of Bluetooth: 5.0 Range of operation: 10M Response frequency: 20 Hz–2 kHz Impedance: 32 Ω The DC 5V charging voltage The earphones can be fully charged three times when the charging compartment is fully charged. Battery capacity: 3.7V, 300mAh; charging time: approximately 1.5 hours. Earphones with a 3.7V, 40mAh battery and an approximate one-hour charging time approximately 3–4 hours of service life (10–12 hours with charging compartment) Operation of pairing: When the