Link: You can link two Bluetooth devices at the same time Bluetooth version: V5.0 Play music / talk time: about 1.5-2 hours Standby time: about 100 hours Charge method: magnetic adsorption Battery Type: rechargeable Polymer Lithium Battery Function: fast charging, high-definition call Voice: can switch between Chinese and English, linked to the state under the press 2 under the boot button Chip: CSR63120 top chip. Specification I9S TWS wireless independent bluetooth headset Wireless binaural bluetooth headset Sound quality: Stereo subwoofer sound Compatible: Apple IOS,Android,Pad,almost all bluetooth device (BT V5.0 or above) PACKAGE INCLUDES : IFANSi9S TWS wirelessBluetooth earphone with charging box 1 x USB cable 1 x Manual