About this item Mini USB Portable FM Radio Speaker Music Player with Rechargeable Li-ion battery. Supports FM Function, FM Frequency Range 87.8-108 MHZ. Supports playing MP3 format music or other media content via Micro SD Card (TF Card) or U Disk. Can play music and be used for language study. Audio output function fits for various devices such as MP3, MP4 players, cell phones, and more. Easy to plug in your smartphone, tablet, laptop, and any audio source that uses a standard 3.5 mm jack. Dimensions: 5 x 0.94 x 2.32 inches.