This 4U, 20-slot chassis features a shorter depth dimension as compared to other 20-slot passive backplane systems. Additional chassis features include a variety of hard drive and optical media drive bay configurations, a front mounted power supply and a robust system-cooling configuration. The 24.5" chassis' depth supports a variety of 20-slot form factor backplanes including single and multi-processor backplanes. The term "20-slot" refers to a backplane's mechanical form factor. The backplane options for this chassis are listed to the left with a summary of each backplane's slot count. The tables below list the chassis' SHB and SBC options. Both option sections include links to detailed specification pages.