The DEDRA rasp is an essential tool for insulation and sticking polystyrene boards. It allows you to mat the surface of the polystyrene before gluing and smooth it out before applying the adhesive mesh. The rasp is made of strong and durable plastic, while the scraping part is steel with a large number of sharp, closely spaced indentations. An undeniable advantage of the rasp is the quick replacement of the scraping part.