"Designed for voice, telephone and router configuration applicationsOur modular cables are constructed from silver satin wiring, and are ideal for costsaving voice and data applications not requiring high data rates. These cables are available in lengths up to 75ft, or can be custom manufactured to meet your application needs. Crossed modular cables are designed for voice, telephone and modem communication applications. These cables are also known as ""rollover"" cables which are commonly used when configuring routers."