"ELASTOMER,MIL-R-25988,TYPE 2,CL 1,GR 40; INNER RING HAS 1.562 IN. DIA HOLE IN CENTER,6 HOLES OF 0.115 IN. DIA; OUTER RING HAS 1.562 IN. DIA HOLE IN CENTER,WITH A 3.900 IN. OUTSIDE DIA,12 HOLES WITH A 0.115 IN. DIA IN OUTER RING; DIAPHRAGM HAS A 3.920 IN. DIA,A 1.540 IN. DIA HOLE IN THE CENTER,0.032 IN. THK; OUTER AND INNER RINGS TO BE BONDED TO DIAPHRAGM; BONDED AREAS TO BE FREE OF VOIDS; EDGES TO HAVE A CONTINUOUS SECURE BOND"