... connecting, clear sound, and anti-interference Frequency: 2.4GHz Bluetooth range: 10m SNR ≥ 90 db Support Windows98/win2000/winXP ... hours Bluetooth call time: up to 7 hours By CE,Rohs approved Accessories: Manual, Speaker Cable,USB Charging Cable, Adapter, ... Microphone(Optional)Certificate: 2012 new smallest bluetooth headsets