Hi Phillip and welcome to the forum.
A slightly fuller explanation of what an R/O is and does.
R/O stands for Reverse Osmosis.
To purify tap water and remove all of the disolved solids and other impurities, one system is to use Reverse Osmosis Membranes, your tap water is pushed through the Membranes at pressure (usually the pressure form your mains is sufficient) after first passing through a couple of pre-filters.
The R/O membranes allows the water to pass through but prevents all bar a tiny percentage of the disolved solids passing through, this is got rid off through the waste water.
The water that comes out of the R/O is then passed through a DI tank, this is a receptacle that holds De-Ionising crystals that remove the rest of the disolved solids, leaving you with the pure, distilled water that is used to clean windows using water fed poles.
As has been said, Reach & Wash is a trade name for a company that make Water Fed Pole-pure water cleaning systems.
If you read through the forum you will find reams of information about WFP window cleaning.
Hope my little explanation hasn't left you more confused than before
Regards,
Ian