talking sound. Its mini size and 4.1g weight of each earphone fit well to your ear canal, and guarantee stability and comfort when doing sports. Fast & Easy Paring: Auto power on and fast pairing between left and right earbuds. Easy and quick to pair with BT-enabled audio devices. Effective distance is about 10 meters in open space. Long Battery Life: 40mAh battery in each earphone ensures about 4 hours of working time. Charged automatically in the 300mAh charging box which enables dual headsets charging for about 2 times. Supports up to 12 hours playtime in total. Born for Sports: 4.1g lightweight and mini size fit well to your ear canal and provide you long time wearing comfort. It guarantees stability when doing sports. With charging box, easy to store and carry anywhere. 7.2mm Drive Unit & DSP Noise Reduction: 7.2mm dynamic drive unit provides powerful low frequency, delicate, soft medium and high frequency. With DSP intelligent noise reduction technology, it can remove the ambient noise, no need to worry about call quality. Specifications: Brand Name: Xiaomi Redmi Model Number: Airdots BT Version: BT5.0 Transmitting Distance: 10m/33ft BT Protocol: HFP, A2DP, HSP, AVCRP Frequency Range: 20-20000Hz Sensitivity: 98dB Impedance: 16Ω Charging Box Capacity: 3.7V 300mAh Earphone Battery Capacity: 2 * 3.7V 40mAh Music Play Time: about 4 hours (depends on music volume) Charging Time: about 1.5 hours for earphones, 2 hours for charging box Color: Black Earphone Item Size: 26.6*21.6*16.4mm/1.04*0.8*0.64in Earphone Weight: 4.1g/0.14oz (Each Earbuds) Charging Box Size: 62*40*27.2mm/2.44*1.57*1.07in Charging Box Weight: 35.4g/1.24oz Package List: 1 * Pair of Earphones 1 * Charging Box 2 * Pairs of Ear Tips 1 * User Manual