Granite Tri-Square Long Form Calibration Certificate No Material Granite Application Grade Laboratory Color Pink Flatness 0.000025 in per 6 in Grade AA Height - Inch 18 in Height (mm) 450 Included Certification Short Form Certificate of Accuracy with NIST Traceability Length (In.) 12 in Length (mm) 300 Number of Finished Faces 3 Number of Pieces Single Block Parallelism 0.000025 in per 6 in Maximum of 0.000075 in Size (In.) 12 in x 18 in x 4 in Size (mm) 300 mm x 450 mm x 100 mm