1.2 micron diameter ultra-fine fiber for excellent wiping performance. Normally it was impossible to completely wipe off with ordinary fibers, which had a thickness of 1 to 2 microns, and about 15 microns. Treshy uses Toray polymer chemistry technology to produce fibers of approximately 2 microns. The ultra-fine fibers penetrate into the oil film one after another, and wipe away the dirt.