I have already used several of these Lenspens, and can only say in principle they are good, but too long one has nothing of it, because at some point, of course, the velvet / felt is saturated with debris, and then no longer cleans correctly. Even worse is the case, which is also described by other reviewers that the velvet eventually slightly to the side slips, and you then rub around the edge of the rubber on the lens, which unsightly black streaks leaves.
For my case now prefer using a normal lens brush, and for subsequent cleaning optics paper. Of these, one is increasing every cleaning over a new leaf, that then again optimally absorbs grease, etc. - without aging, as they quickly occur when Lenspen, depending on the amount and size of lenses, of course.
