These are a good size and nice and soft--they work well on Blu-ray discs with scuffs and fingerprints and slightly less well on DVD's and CD's which do not have the protective coating that Blu-ray discs have.  You might need to use an alcohol based cleaning solution with these to clean some CD's and DVD's.  As for scratches, these won't do much, if anything except on Blu-rays where surface scratches can generally be buffed away.  These are good but recognise their limitations before purchasing.