Incra's Centering Ruler doesn't just take measurements - it marks them automatically - perfectly. Line it up, place a .5mm pencil in the precision slots, and your mark is dead on. The ruler has marking holes every 1/32". It marks the center of your work instantly, and is graduated from the center out in both directions. Also has built in protractor with the most commonly used angles marked and slotted. Stainless steel. USAo