The Mid Atlantic RSHSUB-3D 3-Space Sub-Chassis is a custom rackmount designed for the RSH Series, with a rack unit width of 19 inches. Manufactured by Middle Atlantic Products, this sub-chassis is perfect for organizing and mounting networking equipment, servers, and other devices in a secure and organized manner. Its sturdy construction and vertical design make it ideal for maximizing space and ensuring a stable setup for your networking needs.