up to work. 1 drag 2 to connect two mobile phones at the same time, with a headset USB plug, you can use both ears. [BT4.1 and compatibility] BT4.1, fast transmission speed, low power consumption, stable data transmission, b compatibility, suitable for almost all BT-enabled devices. [Long battery life] Super long standby time to 720 hours (30 days), call and music can be continuous for up to 24 hours, built-in 260mAh battery, optimized through multiple circuits, and effectively save battery energy. [Free your hands] This single-ear headset can free your hands, whether you are driving or working, you can easily operate. When you have two mobile phones, you can support multicasting of two devices at the same time. [Voice prompt] Use the prompt tone to remind the headset of the latest status, such as power on / off, low battery, etc. Supports display of some mobile phone batteries. Support voice reporting of incoming phone numbers. [Ergonomic design] Long-term wearing will not cause pain, skin-friendly materials, ear bones that are ergonomically designed, can be worn comfortably and durable. Headphones with a USB plug for binaural use. Specifications: Product Type: Wireless BT Headset BT Version: 4.1 With Microphone: Yes Support Profiles: A2DP/AVRCP/HFP/HSP Operation Distance: Up to 10m (Free Space) Frequency Response: 20 - 20000 Hz Impedance: 16 Battery capacity: 260mAh Talk Time / Music Play Time: about 24 hours Charging time: 3 hours Color: Black / White (optional) Headphone weight: 13g / 0.46oz Package size: 8.5 * 5.2 * 3.5cm /3.35 * 2.05 * 1.38in Package weight: 57g / 2.01oz Package List: 1 * Headphone 3 * ear hook 3 * earbuds 1 * USB jack headset 1 * data cable 1 * instruction manual (multilingual)