Specfications: Product Name: USB HUB 2.0 USB Version: 2.0 USB Ports: 4/7 port Size: 10.5*3.5*2.1cm, 16.5*3.5*2.1cm Color: White & Black Compatible: Windows, Mac OS or Linux systems Support equipment: mouse, keyboard, U disk, hard disk, camera, radiator, audio and other USB devices Package: 1 x 4 Port USB 2.0 HUB or 1 x 7 Port USB 2.0 HUB Features: Hot Plug & Play USB device Fully compatible with USB specification version 2.0 With blue LED for power ON/OFF switches activate or deactivate individual ports Designed with 4-port, 7-port, this compact USB2.0 high-speed hub is small enough for travel, and cable enough to meet your connectivity needs. Note: The usb hub can not be used to change your phone, it is used for offering more usb ports. The length of 4 port is 13cm; The length of 7 port is 19cm.