Make the call with the onn. 50ft. Telephone Line Cord. Replace your old cord with a high-quality upgrade. Its 50ft. length makes it perfect for swapping out shorter cords to improve the reach of your landline phone. Each end of the cord has a plug designed to fit standard phone jacks. This versatile cord is also ideal for use with modems fax machines and more. The cord’s durable jacket protects it from everyday wear and tear. It has a flexible design that’s perfect for connections in tight spaces. Stay in touch with the onn. 50ft. Telephone Line Cord.