DISA Limited, formerly Equation Summit Limited, is an investment holding company. The Company's segments include Energy Management Services, E-waste/Recycling, Technology, Supply of Construction Materials, and Investment holding and others. The Company's subsidiaries include Disa Digital Safety Pte. Ltd., which is specialized in research and development of security (DiSa Anti-Theft System) and digital authentication (QuickCheck) solutions; Equation Energy Pte. Ltd., which provides energy management solutions to the building industry in Singapore; Equation Resources Pte. Ltd., which is engaged in the business of supplying and trading of construction materials, including sand, granite and coal, and Equation Recycling Pte. Ltd., a provider of environmentally safe processing of obsolete, excess of life commercial, industrial and consumer electrical, and electronic equipment and consumables. The Company has offices in Singapore, Germany, China and the United States.