"CONSISTS OF PRECISION CAST 356-T6 ALUMINUM,SILVER PLATED,3.375 IN. LG,3.250 IN. DIA FLANGE ON ONE END,3.125 IN. DIA FLANGE ON OTHER END,WITH RECTANGULAR WAVEGUIDE SEGMENT WITH SHOULDER IN MIDDLE; LARGE END OF WAVEGUIDE 0.705 TO 0.715 IN. BY 1.460 TO 1.474 IN. INTERIOR AND 0.791 TO 0.799 IN. BY 1.565 TO 1.597 IN. EXTERIOR; SMALL END OF WAVEGUIDE 0.615 TO 0.630 IN. BY 1.367 TO 1.381 IN. INTERIOR; LARGE END FLANGE MOUNTED BY TWO HOLES 0.1244 TO 0.1249 IN. DIA BY 0.093 IN. DEEP SET ON 2.922 TO 2.980 IN. CIRCLE; SMALL END FLANGE MOUNTED BY SIX 0.219 TO 0.222 IN. DIA THROUGH HOLES EQUALLY SPACED ON 2.7 IN. DIA CIRCLE"