A revolutionary combination of noise reduction and cooling. Obsidian Series 550D is carefully engineered for noise reduction and sound isolation. But, it's not just about keeping things quiet - there's amazing cooling potential, lots of expansion flexibility, and the durability that Obsidian Series is renowned for. Superior airflow for high-performance PCs. 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. The silent treatment. With many high-end PC cases, cooling is often provided without consideration for noise. Not so with the 550D: the front and side panels are fully lined with sound-damping material, and the top and side panels have their own sound-insulated vent covers to reduce noise leakage from unused fan mounting locations. The front air intakes are angled away from the front of the case for noise reduction, and the fans and drive bays use silicone mounts to reduce vibration noise. The result is a platform for building high-performance PCs you can live with. Smart features for serious system builders. The extra touches like magnetically mounted dust filters and one-button side panel removal make building fun, and using a 550D-based system a rewarding experience. Expansion is easy, with eight expansion slots, six tool-free hard drive bays with removable caddies and integrated 2.5 SSD support, and four tool-free optical drive bays. The top drive cage can be removed to accommodate GPUs of up to 452mm in length. The diamond-cut brushed aluminum front panel houses two high-speed USB 3.0 connectors and audio ports.