... ATC testing ,CE certificate,ISO9001:2008 VCOM Professional Mini Speaker Product Feature: Frequency:150~18KHz Imdedance:4Ω Distortion:≤ ... ect Bulit -in FMradio module can store up to 25 channels Bulit-in rechargeable battery Support TF card /USB ... Board.Categories of computer electronics: Headphone, Bluetooth Headphone, Earphone, Speaker, Mouse, keyboard,Game Headphone and Keyboard, Game Mouse, Gamepad, ...