Sales and installation of windows and doors, trade in building materials of all kinds, as well as the execution of all related service and repair work. The company may establish branches and subsidiaries at home and abroad, participate in other companies at home and abroad, acquire, sell and manage real estate at home and abroad, hold and manage capital investments of all kinds, acquire, manage and sell copyrights, patents and licenses of all kinds, provide financing for its own account or for the account of third parties, and grant guarantees and warranties for subsidiaries and third parties.