Insize 6900-A12, GRANITE SURFACE PLATE, 18x24x3″, grade A, 6928640359491

Made of granite, free from deterioration or dimensional change over time,
minimal changes in dimension due to temperature changes. Meet GGG-P-463C.
Optional accessory: stand for granite surface plate (part no. 6902),
jack for granite surface plate (part no. 6903).