These two auxiliary ports complement those already included in the Expandable FlexiPort Power Tool Hose Kit (#48212, sold separately). The inside diameters are slightly smaller, allowing you to fit the dust hose onto an even wider variety of tools. As with the originals, the flexible rubber stretches slightly, and conforms easily to oddly shaped ports. The other end of each port threads securely into the stretch hose included with the FlexiPort Power Tool Hose Kit. Note: The two FlexiPort hose systems?12 Fixed-Length and 3 to 12 Expandable?are NOT cross compatible. FlexiPorts with the black threads fit the Expandable Hose only, and FlexiPorts with the gray collar fit the 12 Fixed-Length Hose only.