What the 2-100525-0 Coding Key Does
The TE Connectivity 2-100525-0 is a Z-PACK M.CODING KEY — a blue plastic accessory that keys the backplane connector to prevent mismating of daughtercard modules. It slides into the designated slot on the Z-PACK header or receptacle housing, forcing a specific orientation so only a card with the matching key code can be inserted. This is a field-installable part, not a contact or a housing; it sits alongside the signal pins and changes the mechanical polarization of the connector pair.
Compatibility with Z-PACK Connectors
The 2-100525-0 is listed for use with Z-Pack Series connectors. That covers the standard Z-PACK backplane headers and receptacles — the 2 mm hard metric family, the HM-ZD, and the Z-PACK Slim series. It does not fit every TE backplane connector; if the housing lacks the keying slot moulded into the shroud, this key will not seat. Check that your Z-PACK part number includes a keying feature in its drawing before ordering.