"MATERIAL: PHENOLIC COTTON FABRIC,MIL-P-79,TYPE FBG; OVERALL DIMENSIONS: 1.980 IN. O.D.; 0.251 TO 0.258 IN. I.D COUNTERBORED ON THE CURVED SIDE,0.625 IN. DIA AND 0.380 IN. DEEP; AND 0.880 IN. THICK. SPECIAL FEATURES: FLAT SURFACE IS CHAMFERED ON THE OUTSIDE CORNER,0.150 IN.,45.0 DEG; OTHER SURFACE IS CURVED OUTWARD ON AN EXTENDED RADIUS OF 1.500 IN."