Model: i91 - Color: White + black - Bluetooth version: CSR V2.1+EDR - RF: 2.4GHz GFSK - Bluetooth mode: Headphone / handsfree / A2DP / AVRCP - Working range: 10 meters - Built-in microphone - Supports MP3 format music - Supports TF card up to 16GB - FM frequency: 97.0~108MHz - Up to 5 EQ sound effect modes - High stereo sound performance - Interface: TF + 3.5mm jack + mini USB - Built-in rechargeable battery - Conversation time: 16 hours - Music play time: 13 hours / 10 hours for FM / MP3 - Standby time: 3 days - Package includes: - 1 x Bluetooth MP3 player headset - 1 x USB cable (50cm) - 1 x 3.5mm audio cable (145cm) - 1 x Chinese / English user manual