Gray Universal Sonic Bonded Pads – Fast acting for quick response with a layer of polypropylene that creates high surface area that enables Sonic Bonded Mat to quickly soak up liquids. High absorbency keeps it on the job longer. A random assembly of large diameter poly fibers creates a lofty layer. Ultrasonic Bond Points keep mat intact by fusing layers of fibers together which keeps the mats shape even when completely saturated.