Amphenol

Amphenol is one of the largest manufacturers of interconnect products in the world. The company designs, manufactures and markets electrical, electronic and fiber optic connectors, coaxial and flat-ribbon cable, and interconnect systems.

In the phone business, Amphenol is best known for developing the ubiquitous 25-pair connectors. They're commonly known as "Amphenol" connectors, even though similar, compatible connectors are also made by other companies.

They are used as demarcations ("demarks") between phone company and private wiring, and within phone systems and data networks.