TE Connectivity Economy Interconnection Pin and Socket Contacts Pin and socket contacts for use in Economy Interconnect (EI) housings. These EI pin and socket contacts are made from pre-tin plated brass and accept various wire size ranges. Stock numbers 719-4938, 719-4931, 683-1291, 719-4950 and 719-4941 are for use in low profile Economy Interconnect housings, others are for use in EI housings with a standard profile.