... for voice recording (optional) and FM (optional)Antimagnetic interference function Material: Aluminium alloy Power source: Li-ion battery / DC5V ... /TF card, USB disk, FM, etc. Supports Line IN function, receiving the audio source from MP3, MP4, PC, Notebook, ... transmission, fully compatible with USB1.1. Supports the calendar, time. Built-in high capacity rechargable battery, support long play. ...