An adjustable spool recently introduced by Cooper B-Line has been designed to assist cabling installers and technicians with cable management. The spool comes with preinstalled screws and can be mounted inside cable pathways. It is expandable, adjusting between 5 and 8 inches without the use of tools. The spool has a 1.125-inch radius, which Cooper B-Line says serves to protect cable bend radii.
According to Cooper B-Line, users just rotate the spool to unlock it, push or pull it to the desired depth, and rotate it back into the lock position. The company has included an instruction sheet on its website, which you can access here.