Corsair Obsidian Series Black 550D Mid Tower Computer Case Six tool-free hard drive trays with integral SSD support and soft silicon sound dampening Four tool-free optical drive bays Front panel USB 3.0 connectors and audio connectors Cable routing cutouts with rubber grommets Removable, reversible front panel Eight expansion slots for multi-GPU compatibility Three 120mm fans Top panel is compatible with 240mm radiators for dual-radiator Hydro Series CPU coolers and liquid cooling systems