In the 1960s, almost all Swiss watches had Glucydur balance and Nivarox hairsprings. The anchors, escape wheels and other watch mechanisms were also made of non-magnetic metals or alloys.[citation needed] Another way of making a watch non-magnetic is to house the entire movement into a case made of a highly permeable (magnetically conductive) material. The movement is covered by an additional soft-iron clasp to prevent the forming of magnetic fields inside the watch itself.[citation needed]