TE Connectivity (often shortened to TE) is a global manufacturing company mostly associated with the production of connectors and components for various industries, such as telecommunications, automotive, and medical. 743-4 refers to one of the product series offered by TE. Specifically, the 743 series is a rectangular, shielded cable connector and contacts that is usually used in applications that require EMC/EMI shielding. The "-4" indicates that this product series is composed of four pieces or components: a Housing, Contact, Silicone Filler, and Plating material. The Housing is an outer casing typically made of aluminum, the Contact is a metal contact for electrical connection, the Silicone Filler is a non-conductive gel used to ensure optimal connection and protect the contact from corrosion and abrasion, and the Plating material is typically gold or silver to improve the contacts resistance to corrosion.