APC SX Vertical Cable Manager

Cable manager for the APC SX series of racks.
Designed to fit the entire width of the lacing strip - put both your PDUs on the other side of the rack.
One big well for copper, and a smaller well for fiber. You can use velcro strips to close the manager, or use the cap that is also included here.

5 to 7 of these per 42U rack make a better manager than APCs vertical cable management rails.

I found that the semi-flexibility of PETG works well here, as you need to bend it a good bit to snap