This block contains (4) 1/32″ diameter thru-holes located at 0.100, 0.200, 0.300, and 0.400″ from the scanning surface with corresponding beam exit marks for 70° engraved on both sides. Also contains (2) EDM notches at 0.050 and 0.100″ deep x 0.011″ wide x 0.500″ long. In accordance with PH Dwg No. 10539 Rev. 1.