Indoor Ultra Pure Water Cleaning System is for indoor glass and non-porous surfaces. Reaches difficult areas without dripping on or having to move furniture. It combines the cleaning power of pure water and microfiber in a light, compact and entirely mechanical tool (no cords, no batteries, etc). Keeps glass clean longer. With no chemical residue being left behind on the glass dirt will not be attracted, reducing the frequency of cleaning intervals. Fill with pure water from HydroTube™, Hydro Cart or Ready Pure systems.