seen-does-not-mean-understoodabout 10 cmHousing flange centered on both sidesReinforcedhousing wallTension screwSpacer bushingStiffening braceEdges of thecontainment ringare pulled inRing space filledwith honeycombThin-walled structurewith a conical shape Just because one has seen something, does not mean thatone has understood it. Often, one does not register anything because one does not know what to look for ordoes not understand what one has seen. ?