Check the setting of answering method on your cell phone and confirm if need some setting when connecting the Bluetooth device.
Support HSP, HFP, A2DP, AVRCP. Provides in-call stereo sound.Greatly improve the transmission speed and providing you with a low-latency listening experience.
Pick up 2 headsets from the charging case and they will connect each other automatically. Then only one step easily enter mobile phone's Bluetooth setting and choose "TOZO-A1" to pair the earbuds.