Longer lifespan when sanding wood and paint. The Bosch Surface Structure combines advanced techniques for bonding and surface coating to optimally fix the grain on the substrate. It is so strong that the Bosch EXPERT Combi Block sanding pad does not lose its grit when sanding edges and corners. Additionally, clogging of the sanding sponge is minimized, as dust can easily be knocked out or washed off. There are also shapes for even pressure on the surface.