Bluetooth version: V4.1
Working Voltage: 3.2V - 4.2V
Sensitivity: -42dB±2dB
Frequency Range: 2.4-2.48Ghz
Talk/Listening time: up to 120 minutes listen or talk
Standby time: up to 8 days
Auto Power-off technology: Power off when no connectivity for 5 minutes.
Operating distance(range): up to 10m/33 feet
Headphones weight: 5 grams per earbud
Noise reduction: Full duplex echo cancellation; Real time noise reduction; Voice clarity
Moisture protection: Design for sweat and moisture protection
Charge connector: Micro USB charging
Battery type: Rechargeable, non-replaceable lithium-ion polymer
Bluetooth 4.1 + EDR: Advanced Audio Distribution Profile (A2DP), Audio Video Remote Control Profile (AVRCP), Hands-free Profile (HFP) and Headset Profile (HSP)

Package included:
2 x LarKoo Bluetooth Stereo Earpbuds
4 x Earcaps
1 x Charging Station
1 x Micro USB charge cable
1 x User Manual

Note:
When charging, red light is on; When finished charging, light off; When headset is put in the charging case, hedset will be powerd off automatically; When several minutes after the low battery alert, headset will be powerd off.
More instructions in the User Manual