Granite Tri-Square Long Form Calibration Certificate No Material Granite Application Grade Inspection Color Pink Flatness 0.000050 in per 6 in Grade A 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 0.000050 in per 6 in Maximum of 0.00015 in Size (In.) 12 in x 18 in x 4 in Size (mm) 300 mm x 450 mm x 100 mm