"COPPER ALLOY,MIL-C-20159,TYPE 1,12.875 IN. OD,17.250 IN. MIN AND 17.255 IN. MAX ID,15.120 IN. MIN. AND 15.125 IN. FLANGE ID; TWENTY 0.938 IN. DIA HOLES ON A 22.500 IN. BLT CIR; TWELVE 0.750NC-5 HOLES ON A 18.750 IN. BLT CIR DRILLED 0.100 IN. DEEP; 5.938 IN. THK"