Starrett 272MA Fillet or Radius Gauge, 0.75-5mm Range (Concave and Convex), 0.25mm Increments, 18 Leaves, Millimeter ReadingThe Starrett 272 Fillet or Radius Gauge is an external and internal radius on each leaf permits both concave and convex surfaces to be measured. The leaves are specially shaped for use in any position at any angle to measure fillets and radii in corners or against shoulders. Each leaf is stamped with the radius size and has an eccentric mounting for clearance between the leaf and the case when the gauge is opened. 18 Leaves, 0. 75 5mm Range by 0.