Gas compressors; Grinding and polishing machines; Lifting jacks other than hand-operated; Machine tools, namely, powered machines for cutting or shaping or finishing metals or other materials; Paint sprayers; Polishing machines for use in grinding and polishing metal, wood, ceramics and plastics; Power-operated polishers; Screwdrivers, electric; Water aeration systems comprising water pumps, air compressors and air blowers