Cooler Master K550 is a mid-tower case that supports ATX and Micro ATX motherboards. It features a mesh front bezel for improved airflow, a red LED fan in the front, a black fan in the rear, and the option to install additional fans on the top, side, and bottom. The case has seven hidden 3.5-inch drive bays, two hidden 2.5-inch drive bays, and three exposed 5.25-inch drive bays. It also includes a tool-free assembly system for easy installation of 3.5-inch hard drives. The K550's I/O panel includes two USB 2.0 ports, one USB 3.0 port, an audio jack, and a microphone jack.