... 4.ATC testing ,CE certificate,ISO9001:2008 VCOM Professional Mini Speaker Product Feature: Frequency:150~18KHz Imdedance:4Ω Distortion ... VCOM brand:History:Established in 1994. Group:3 Sales Company in Guangzhou, 2 Factories in Dongguan, 1 Factory ... Board.Categories of computer electronics: Headphone, Bluetooth Headphone, Earphone, Speaker, Mouse, keyboard,Game Headphone and Keyboard, Game Mouse, ...