An electrical connector for use in an electrical connector system which controls cross-talk, signal radiation and impedance, the electrical connector comprising: a plurality of modules, the modules having mating ends and mounting ends; each of the modules of the plurality of modules comprising: a conductive first housing, the first housing having at least one second housing recess provided in a first surface of the first housing, the first housing having ground contact receiving channels provided in the first surface of the first housing; at least one second housing provided in the at least one second housing recess, the at least one second housing being made of insulative material, the at least one second housing having signal contact receiving channels provided in a first surface of the at least one second housing; signal contacts positioned in the signal contact receiving channels of the at least one second housing; ground contacts positioned in the ground contact receiving channels of the first housing (41, 141), characterised in that the first housing has ground contact receiving channels provided in a second surface of the first housing, and respective ground contacts of the ground contacts extend from in the ground contact receiving channels provided in the first surface of the first housing to the ground contact receiving channels provided in the second surface of the first housing and have projections which extend from the second surface to engage grounding contacts of a mating connector. a plurality of modules, the modules having mating ends and mounting ends; each of the modules of the plurality of modules comprising: a conductive first housing, the first housing having at least one second housing recess provided in a first surface of the first housing, the first housing having ground contact receiving channels provided in the first surface of the first housing; at least one second housing provided in the at least one second housing recess, the at least one second housing being made of insulative material, the at least one second housing having signal contact receiving channels provided in a first surface of the at least one second housing; signal contacts positioned in the signal contact receiving channels of the at least one second housing; ground contacts positioned in the ground contact receiving channels of the first housing (41, 141), characterised in that the first housing has ground contact receiving channels provided in a second surface of the first housing, and respective ground contacts of the ground contacts extend from in the ground contact receiving channels provided in the first surface of the first housing to the ground contact receiving channels provided in the second surface of the first housing and have projections which extend from the second surface to engage grounding contacts of a mating connector. a conductive first housing, the first housing having at least one second housing recess provided in a first surface of the first housing, the first housing having ground contact receiving channels provided in the first surface of the first housing; at least one second housing provided in the at least one second housing recess, the at least one second housing being made of insulative material, the at least one second housing having signal contact receiving channels provided in a first surface of the at least one second housing; signal contacts positioned in the signal contact receiving channels of the at least one second housing; ground contacts positioned in the ground contact receiving channels of the first housing (41, 141), characterised in that the first housing has ground contact receiving channels provided in a second surface of the first housing, and respective ground contacts of the ground contacts extend from in the ground contact receiving channels provided in the first surface of the first housing to the ground contact receiving channels provided in the second surface of the first housing and have projections which extend from the second surface to engage grounding contacts of a mating connector.