Twinaxial (or sometimes referred to as "Twinax") is a communication transmission cable similar to a coaxial cable. Instead of one inner conductor, it has two centre copper insulated wire conductors. The two centre conductors are enclosed by a shielding spacer, which, in turn, is enclosed by a tubular outer conductor, this is typically a wire metal braid, foil or sometimes both. The assembly is then concealed with an insulating and protective outer layer, offering more protection from environmental influence.

The benefits of this construction:

• Cable losses are lowered

• Provides defence against ground loops and capacitive fields

• It defends against low-frequency magnetic noise that passes through the copper braid

• By consuming more copper wire in a tight intertwine braid, it increases coverage to 90 percent

Originally, Twinaxial cables were designed for IBM computer hardware and designed by IBM for high-speed connections (1Mbit/s) and can have multiple addressable devices per connections. More recently, the Twinaxial cable has seen wider use in the market, particularly for applications that require high-speed differential signalling in a short-ranged environment, such as in local area networks (LAN) offering a cost-efficient solution.