The EURACK/USRACK chassis is designed to hold up to 14 single-width fiber optic modules. The internal power supply is 4 RU high. The chassis is designed to mount into an EIA-standard, 48.26 cm (19-inch) rack. Optional single-width blank modules (RACK1B) can be inserted into empty module slots.

The EURACK/USRACK fiber card cage features automatic electronic current limiting at each module rather than limiting current
at the power supply. With this design, if a fiber module fault occurs, only the faulty module will shut down. All other modules within the rack will continue to operate unimpaired.

The automatic current limiting feature of the EURACK/USRACK is also self-resetting. This allows the unit to handle a temporary or intermittent fault or overload. Modules in the chassis are hot-swappable, allowing the rack to remain powered when removing or replacing modules.