The OneChassis OC339F-M is a 3U rackmount case designed to fit ATX motherboards. It includes two pre-installed 80mm cooling fans to ensure optimal airflow and thermal management, protecting against overheating of drives and components. This 3U rackmount case supports up to eight 3.5″ hard drives or three 5.25″ optical drives and offers five PCI expansion slots for added flexibility. It is commonly utilized in automation, equipment manufacturing, power monitoring, communication, security, and defense sectors. Compatible with ATX motherboards Works with ATX power supplies Made from SGCC steel Includes two front USB 2.0 ports It Accommodates eight 3.5-inch hard drives Fits three 5.25" optical drives It comes with two 80mm cooling fans Power supply not included