Bluetooth version: jl6936d5.0, high-definition binaural call Transmission distance: barrier-free distance 10-20 meters Product speaker: high-quality composite membrane copper ring speaker Product chip: true stereo chip Working time: (3-4 hours) Charging warehouse standby time: 30 days Headphone battery capacity: pure cobalt 30 mA Rechargeable battery capacity: pure cobalt 260 mA (with IC protection board) Packing size: 12*10*3.5cm Packing standard: earphone*2 + charging bin + charging cable + manual + packaging box + certificate