High quality, industrial grade, professional tools. Heat treated for optimum strength and ductility. Finished with Eklind black finish to resist rust. Fold-up sets include a variety of popular sizes in one convenient handle to keep you from losing individual keys. - Eklind classic steel fold-up sets are compact to fit most easily in your pocket. Fold a key out to a right angle to get maximum leverage. Fold a key out completely to operate like a screwdriver.