iStarUSA D2-200L-M4SA is a 2U rackmount chassis that can hold up to four hot-swappable SATA II drives, providing high density and high availability for storage servers. It features three PCI cutouts that support PCI, PCI 64bits, AGP, and PCI-Express add-on cards, making it a versatile solution for various applications. The front access USB 2.0 ports allow for easy connectivity to external devices, while the three 80mm cooling fans ensure optimal airflow to prevent overheating. The removable air filter helps to keep the system clean and dust-free, extending the lifespan of the components.