DUST-CLOTH MF’s are made from a very soft weave of micro fiber cloth that has been tested repeatedly not to scratch sensor filters or their coatings. The main benefit to these micro fiber wipes is that they are designed not to produce loose fibers. The sides of the wipes are heat sealed so fibers can't break free. Seeing that when wrapped you are only using the center part of the wipe, the sealed edge will not come close to the sensor filter. The Dust-Cloth MF wipes are also more absorbent than regular non-woven wipes which helps to reduce excess cleaning fluid escaping the wipe & seeping under the sensor filter frame. These wipes are sized 3"x 3" due to their thickness. This is plenty of cloth to produce a nice wrap & still have a good sight path to the sensor filter.