The FiberRunner? 1-Port Spillout is used in cable routing systems to route into 1.5 inch (38mm) diameter split corrugated tubing directly through a hole cut in the sidewall of the 4x4, 6x4, and 12x4 FiberRunner? Channel or 4x4 Fiber-Duct? Channel. It provides a 1 inch (25.4mm) bend radius control at the exit. It securely holds split corrugated tubing to ensure system integrity and easy access to add or remove cables.