Features: After a simple bluetooth pairing, they will connect automatically once you open the case; you can listen to music or make phone calls when wearing them. Infrared sensor can sense when the earbuds are in your ears and when you take them out. Adopts balanced armatures + dynamic drivers with independent equalization (EQ) adjustment to achieve crisp treble, natural alto & deep bass. Adopts AAC technology to improve transmission efficiency and present more details. Built-in G-Sensor that simplifies every operation into an elegant & efficient double-tap. Pair key: 1. Use it in first time, press it in 2 seconds, charging box will be turned on; 2. When the Headphone t is in the charging box, press pair key in 2-10 seconds, the headphone will be in the status of pairing; 3. When the Headphone t is in the charging box, press pair key over 10 seconds, the headphone will recover factory settings. Note: Only Chinese voice prompts. - Specifications:General Specification Wearing Type In-ear - Technical Parameters Microphone Yes bluetooth Version V4.2 Transmission Distance 10m Receive Sensitivity 120d - B Impedance 32Ω Frequency Response 20-20k - Hz Battery Capacity Each earphone: 55m - Ah, 3.7V Charging Time (h) 2h Working Time (h) 3-10h Standby Time (h) up to 40h - Package Included: 1x For Original HUAWEI FreeBuds TWS bluetooth Earphone with Charging Box 1x Type C charging cable 1 set of ear support/ earplugs (L/M/S/XS)-M is put on the headset 1x Chinese Manual