Abrasive disks for power-operated sanders; Electric sanders; Grinding and polishing machines; Kits comprised of sandpaper sheets configured to fit power-operated sanders; Orbital sanding machines; Polishing machines for use in grinding and polishing metal, wood, ceramics and plastics; Polishing system for use in single-head machines comprising grinding and polishing discs for stone profiling and edges; Power-operated polishers; Power driven polishers; Sanding pads for power-operated sanders