"Typical use for such an item would be for flex to an electric heater or something similar. But just to be different ...... I bought 2 of these to fit to the wall behind one of my hifi speakers, which is beside the amplifier. So I now no longer have 9m of thick speaker cable (thicker than most mains cables) overfilling a small space. Instead, the cable goes into the wall through one of these, 8m hides inside the cavity of the partition wall, and the rest emerges through the other one to reach the speaker. The grommet in the centre can be cut as required to make a tight fit round the cable. Attached by an Appleby dry lining box, simple neat finish."