Abstract: A modular jack is disclosed and includes an insulating body having a plug insertion hole formed in a front end of the body for receiving therein a complementary plug having contact means. The body includes contact insertion holes communicating with the plug insertion hole and contact insertion slots inside the plug insertion hole at entrances to the contact insertion holes. Jack contacts are inserted into the contact insertion holes with free and portions of the contacts exposed inside the plug insertion hole in the body for contacting the plug contact means. The contact insertion slots are sized relative to the size of the jack contacts so that there is provided an interference fit therebetween to maintain proper positioning of the contacts and to prevent the contacts from backing out of the contact insertion holes.