Very happy to serve you, dear customer! 1. we will DO NOT put any invoices, QR codes, promotions in the shipment, So Dont worry, Just buy it, we will do anything well for you. 2.We are guarantee each device be tested rigorous before shipped out, SO all products can guarantee 100% high quality before sent out. If you have any questions, please contact us. Thank you very much !!! Features Bluetooth version: version 5.0 Transmission distance: outdoor straight line distance 10-15 meters Battery capacity: pure cobalt battery 60 mAh Function: fast charging, HD call Listening to music time: 1-2.5 hours up and down / pause playback Talk time: 2-3 hours Standby time: 130 hours Charging time: 1hours How to pair headphones simultaneous: (1) 2 headphonesual press and start to see the red and blue flashing and then release the hand (2) 2 headphones will be automatically paired together, 1 of which will not flash. Is the pairing success (3) At this time, turn on the phone Bluetooth again to connect with the phone. Button function: long press, power on, long press, power off, click music pause/play, call answer/hang up, double click next song Note: Automatically shut down after three minutes without connecting the headset to the headset after booting. Charging tips: Headphone charging reminder light: headphone charging red light Charging box charging tips: 1. When the charging box is charging the earphone: the charging box LED light is always on, and the LED light is off after the earphone is full. 2. When charging the charging box: the red LED of the charging box flashes, and the red LED is always on after being fully charged. i7S-tws : 2 x pair of headphones (left and right headphones) 1 x charging box 1 x USB charging cable 1 x user manual The headset button shape will be sent randomly. Please know, thank you!