Features: Telephone Answering Function -Built-In Microphone,allows you to talk through the speaker for hands free calling. Extended Playing Time -Allows you play long time with the rechargeable, high capacity battery. Multi-play Function - Quickly syncs and automatically pairs to your device like Android, iPhone, iPad, tablets, smartphones, iPods, MP3, MP4 and other Bluetooth enabled digital players or media devices with aux port in seconds. -This machine plug TF card, can automatically play stored music files. Specification: Bluetooth Version: 2.1+EDR Bluetooth IC: JR Output power: 3W * 2 Working voltage: 5V Frequency response: 100 HZ - 18 KHZ Signal-to-noise ratio: 80 dba or higher Distortion: 1% Audio input: Bluetooth, TF card, U disk, AUX Speaker: 40 mm, 4 ohm Battery: Built-in battery 1200 mah Input sensitivity: 450 + 50 mv Size: 180*65*70mm