[Support Mini ITX Motherboard] ITX Motherboard dimension 6.7 * 6.7 in (17*17cm). ^^ [Support Flex or 1U Power Supply Unit] Flex PSU dimension 3.21 * 1.59 * 5.91 in ( 81.5 * 40.5 *150mm). 1U PSU dimension 3.94 * 1.59 in (100* 40.5 mm) maximum length 7.48 in (190mm). ^^ [Support 1 Single Slot Full Height PCI-e Expansion Card] To add video card or network card or more. ^^ [Come With 2 Front USB 3.0 ] USB 3.0 for faster data transfer. ^^ [Come With 1 8cm Replaceable Fan] Pre-installed 80*80*25mm chassis fan.