The SilverStone RAC45-280MK is a 280mm radiator mounting kit designed for SilverStone rackmount chassis, including the RM45-360, RM600, and RM61-312 models. This kit replaces the 360mm front radiator mount space in exchange for accommodating a 280mm radiator, freeing up space for adding two 5.25" drive bays. It enhances chassis versatility by offering improved cooling options, expanded storage capacity, and optimized airflow management, resulting in superior thermal performance and system stability; perfect solution for maximizing system functionality and efficiency.