Best thing ive used for internal. Just done a big internal office clean, 130 internal windows plus 20 internal glass walls. Paper work and computers every where, with the vikan internal kit you dont have to worry about getting water on paper work or pcs. I think the kit saved me at least 2 hours on this job.
Only problem was needed new spray bottle half way through and could have done with at least 10 microfibre pads instead of the 5 that comes with the kit.