The PatchRunnerâ„¢ 2 Vertical Cable Manager Pass-Through Hole Grommet protects cable as it passes from front to back through the manager backbone. The rubber grommet easily installs in the pass-through hole to provide proper bend radius and ensure cable performance. Each part number contain five grommets, so it can be used with 45 RU or 52 RU managers. The grommets are black and are sized for 3 inch diameter pass-through holes.