"DISC HAVING A CENTER THRU HOLE WITH A 0.255 INCH DIAMETER; HAVING 6 THRU HOLES SPACED 60 DEGREES APART ON A 3.750 INCH DIAMETER FIELD, EACH WITH 0.562 INCH DIAMETERS; HAVING 16 THRU HOLES SPACED 22.5 DEGREES APART ON A 9.500 INCH DIAMETER FIELD, EACH HAVING A 0.755 INCH DIAMETER; HUB PORTION OF DISC HAS 5.500 INCH DIAMETER AND IS 1.500 INCHES IN HEIGHT"