Obsidian Series 550D comes with two front-mounted 120mm intake fans and one 120mm exhaust fan more than enough for delivering the airflow required for a high-performance system. But if you're pushing past high performance and into the realm of extreme-performance overclocking, there's room for a lot more. The top panel provides room for two 120mm or 140mm fans, or a 240mm radiator for compatibility with Corsair Hydro Series CPU coolers and other liquid cooling systems. The side panel has mounting points for another two 120mm or 140mm fans for cooling multiple GPUs. In total, the 550D offers ten 120mm fan mounting points, six of which can also accommodate 140mm fans. model : CC-9011116-WW tag : Computer Cases