Features:1. listening to the song correct; support songs and call; 2. remind call number; the last call back; all intelligent Chinese and English voice prompts; boot; pair; shut down the phone power will be low voice prompts;3. Power capacity will show on your Iphone; you can see the power situation anytime; do not worry about the electricity ; make your life without worry;4. One to two connections; can be connected to two mobile phones at the same time5. Bluetooth headset connected to the phone after the shutdown  ; and then open the Bluetooth headset will connect back to the phone  automatically  ; more convenient;6. Intelligent compatibility: support all Bluetooth mobile phone; tablet; notebook; singing it; QQ music; movies; etc.; universal all mobile phoneSpecification:1. Driver: 15mm2. Impedance: 32 OHM3. Bluetooth version: Bluetooth v5.0 + EDR4. Bluetooth use band: 2.4GHz5. Power level: CLASS II6. Output power: 30mW7. Bluetooth distance: 10 meters barrier8. Frequency response: 20-20000Hz9. Operating voltage range: 3.0V-4.2V10. Mic sensitivity: -42dB11. With A2DP / AVRCP high quality stereo audio transmission and remote control protocol12. Powerful noise de-noising circuit (active noise reduction)13. switch between Chinese and English (boot does not connect Bluetooth state; press the switch 2 times; hear the tone switch successfully)14. Talk time is about 2-3 hours15. music time about 1.5-2 hours16. Standby time is about 100 hoursPackage Includes:2 x i7s tws bluetooth earphones (left and right earphones)1 x Charging box1 x USB Charging Cable1 x User Manual