Rockwool A/S, also known as the ROCKWOOL Group, is a Danish multinational manufacturer of mineral wool products headquartered in Hedehusene, Greater Copenhagen, Denmark. The company's R&D unit, employing 100 people as of 2016, is co-located with the headquarters in Copenhagen. Rockwool was the world's largest maker of insulation materials in 2009, but had fallen to the second largest by 2016. As of 2009, 90% of the company's revenue came from the sale of insulation products, while 80% came from sales in Europe. Wikipedia