This part of IEC 60917 provides additional dimensions for a modular range of subracks and associated plug-in units based on IEC 60917-2-2. A typical subrack consists of a frame design with mounting dimensions for installation into racks or cabinets in accordance with IEC 60917-2-1. The aperture dimensions of a subrack are specified in order to meet the mounting dimensions of front plug-in units. This part of IEC 60917 comprises – additional dimensions for subracks and subrack associated plug-in units with injector/extractor handle; – dimensions for basic electromagnetic shielding provisions; – dimensions of the key/coding system for subrack and plug-in units; – dimensions of the alignment pin for front panel and plug-in unit; – dimensions of electrostatic discharge provisions; – dimensions of rear-mounted plug-in units. Connector-related dimensions are given in Annex A. In order to ensure the compatibility of plug-in units into the subrack, inspection dimensions and connector-dependent dimensions are defined. NOTE The drawings used in this part of IEC 60917 are not intended to indicate product design, only the specific dimensions that are used.