W.W. Grainger distributes maintenance, repair and operating supplies to businesses, government agencies and institutions, offering a broad catalog of industrial products including tools, safety equipment, fasteners and other supplies needed to keep facilities and equipment running. Its distribution business serves as an intermediary between thousands of manufacturers and the many businesses that need a reliable, convenient source for a huge variety of maintenance and operating supplies rather than dealing with numerous individual suppliers directly. Grainger's scale and broad product catalog let it offer customers fast delivery and consistent availability across an enormous range of products, advantages that are difficult for smaller distributors to replicate. The company's revenue is tied to overall industrial and commercial activity levels, since maintenance and operating supplies demand tracks how much businesses are operating and maintaining their facilities and equipment.