Product Name: Precision Granite V-Blocks Model NO.: see specific list Material: Jinan Black Granite Grade: 00 / 0 / 1 Trademark: JINGDA Transport Package: Wooden Case Specification: see specific list Origin: China. Product Description -Uniformhardness<o:p>-Accurateunderaload<o:p>-Lowporosity<o:p>-Easytokeepclean<o:p>-Doesn'trust<o:p>-Doesn'twarp<o:p>-Nomaintaincerequired<o:p>-Non-magneticTpye (mm)Flatnessof workingsurfaceParallelismbetween V slotand bottomsurfaceParallelismbetween V sloand sidesurfaceSymmetrybetween V slotand end surfaceSquarenessbetween V slotand end surfaceSquarenessbetween V sideand bottomsurfaceHeight Differenceof the v slot witha matched pairPrecision grade ( μm)0101010101010163 × 63 × 90°1.5348488168848510100 × 100 × 90°2448488168848510160 × 160 × 90°2.5551051010201010510612Package