Zalman GS1000 Full Tower Enclosure (Titanium) The GS1000 is designed for optimal airflow on both intake and exhaust. Vented front HDD door allows cool air to enter helps cool the drivers - The ventilated floor panel helps cool the PSU and other components. The optional 120mm fan ports will allow additional fans to further enhance cooling performance. The top vents coupled with a 120mm fan are very effective in exhausting hot air. The optional 120mm fan ports will allow additional fans to further enhance cooling performance. Tool Free design allows for easy installation. Rubber damper and hook system makes swapping out hard drives hassle free. Tool-free installation for 5.25 devices. - Thumb screws for easy PCI card removal and installation.