THIS IS AN ATCO PRECISION COMPOUND FINE POLE SINE PLATE, ALSO KNOWN AS A MAGNA-SINE. THE DIMENSIONS OF THIS COMPOUND SINE PLATE ARE 8-1/2 INCHES IN HEIGHT, 6 INCHES IN WIDTH, AND 12 INCHES IN LENGTH. IT IS DESIGNED FOR PRECISE TOOLING AND MAGNETIC CHUCK APPLICATIONS, ENHANCING ACCURACY IN WORKSHOP PROJECTS.