Fowler Full Warranty AGD Indicator and Magnetic Back, 52-520-485-0, 0-1" Measuring Range, 0.001" Graduation Interval, 1" Travel, 2.25" Diameter Full 1 year warranty offered by Fowler High Precision, an American company Dial indicator with magnetic back can be positioned on most metal surfaces to measure surface variations in fractions of an inch 2-1/4" dial diameter with continuous 0-100 dial reading, tolerance markers, 0.001" graduations, and revolution counter for a wide range of travel Stem has 1" travel and carbide ball contact point for a longe measuring range and long life Magnetic back has a protective coating and is used to position indicator on most metal surfaces, meets AGD Group 2 specifications for dial face diameter