ProPlus Heavy Duty Oval Sponge, 6¼"x4¼"x2-1/8", Polyester. Armaly ProPlus Contractor Grade Sponges are made with our HDQM Polyester sponge material. This time tested formula provides superior strength and a cell structure that washes, wipes and rinses dirt and excess paste faster…to meet the demands of the professional paper hanger, painter and wall washing contractor.