From the Manufacturer
Steel protractors are for setting bevels and measuring and marking angles. It has permanently etched graduations for 0 to 180 degrees in opposite directions. It has a 3-3/8″ x 2″ head. The 6″ adjustable protractor arm locks into desired position with knurled thumb nut. Square head.
Made of ground stainless steel. Permanently etched graduations from 0 to 180 in opposite directions. 3 3 8″ x 2″ head. 6″ adjustable protractor arm locks onto desired position with knurled thumb nut.