- The system dimensions of the RFI- SHIELDED subrack are based on those of the FLEXIBLE subrack as a logical further development to produce the perfectly shielded subrack. This allows unrestricted use of the extensive and complete range of accessories. The special design features of the RFISHIELDED subrack: • The refined RFI shielding concept enables high shielding effectiveness. • The stable stainless steel contact springs ensure permanent and reliable bonding, even after a large number of plug-in cycles. • The perforated RFI cover plates guarantee optimal air flow for improved heat dissipation. • The use of high-quality, seawater-resistant aluminum alloys and stainless steel materials removes, for the most part, the need for unnecessary, environmentally harmful surface treatment. THERE ARE 3 VERSIONS OF THIS SUBRACK 1. Subrack RFI-SHIELDED The standard RFI-shielded version. 2. Subrack RFI-SHIELDED IEEE The front is in accordance with IEEE 1101.10. The special profile rail is designed for the use of inser tion and removal handles (optionally with a hot swap function) for overcoming high insertion and removal resistance. The card guides are fitted with mechanical coding systems and special bonding for electrostatic discharge. 3. Subrack RFI-SHIELDED IEEE / Rear I/O The front and the rear are in accordance with IEEE 1101.10/11. This enables insertion and removal of modules with a front panel from both the front and the rear of the subrack.