Handy adapter for the WV-5 (and 2, and probably more)
The box contains 2 extensions, one for the cleaning mop, and one for the vacuum cleaner. There's also an adapter for the smaller vacuum cleaner.
These extensions seem to work with pressure on them, you don't have to screw anything to fix them on a given length, you use it either folded, or extended to its full length, and in the last form there's nothing to hold it extended, just the position and the vertical pressure.