Abstract: In order to provide a modular housing system for electrical contacts whereby contact banks of required size may be made up from common or modular parts, a contact module comprises a body 22 adapted to be slidably received and located in a housing 21, and at least one contact 32, 33 received in an individual groove 24 in the body 22 so as to project from the body 22. The contact 32, 33 has a configuration 37 co-operable with a corresponding formation 27 in the groove 24 to prevent longitudinal movement of the contact 32, 33 in the groove 24. As illustrated, the configuration is a slot 37 formed in part of the contact to locate on a corresponding abutment 27 in the groove 24. The slot 37 is received by an undercut in the abutment 27 to inhibit lateral movement of the contact 32, 33.