Bluedio S3 Bluetooth 4.1 sports headset As your personal music device, 1 gram of weight is enough to affect using experience, so as a good headset, lightweight is a must. Compare to 15-20 grams weight of other headsets, customize only 11.5 grams of S3, has created unprecedented breakthrough. Lightweight as nothing on ear, but accompany with you in every moment. S3 is wireless and humanized for you. Connect to 2 phones simultaneously. Voice command say "Yes" or "No" decide whether to pick a call; Press MF button 2 seconds, then release, to activate voice assistant of mobile phone, e.g. Siri(Phone feature); last but not the end, press MF button and Vol(-) simultaneously to choose voice promts(Chinese/English). Specification: Bluetooth version: V4.1 Frequency range: 2.4GHz-2.48GHz Operating distance: up to 10m (free space) Bluetooth profiles: A2DP、AVRCP、HSP、HFP Standby time: up to 180hrs Talk/music playtime: about 5 hours Charging time: about 2 hours Frequency response: 20Hz-20kHz Operational temperature: -10 to 50°C Accessories: S3 BT sports headset 1pc USB charging cable 1pc User manual 1pc