Extend a Thunderbolt-equipped workstation with three full-length PCIe slots in a rackmount enclosure designed for serious expansion. The Echo III Rackmount gives teams a practical path to add capture cards, storage controllers, audio interfaces, and specialized I/O without moving to a larger tower. That matters when the host system is already approved, deployed, or standardized, but the workflow now needs more bandwidth and more cards. For production environments, the value is control. Keep the compute platform where it belongs and place the expansion hardware in a rack-friendly chassis that fits into existing infrastructure. This approach helps preserve desk space, simplify service access, and support repeatable deployments across studios, labs, and technical workstations. Sonnet built this system for users who need PCIe expansion without compromise. Three slots and full-length card support make it suitable for higher-end peripherals that cheaper adapters cannot accommodate. If your team depends on specialized hardware, this enclosure provides a cleaner, more scalable way to connect it through Thunderbolt.