By beveled, what is meant is that the distal end surface of the optic fiber and the distal, annular end surface of the cannula are both formed at an oblique angle to the center axes of the cannula and {HEAD ~ the portion} of the optic fiber passing through {TAIL ~ the cannula} 
passing through
By beveled , what is meant is that the distal end surface of the optic fiber and the distal , annular end surface of the cannula are both formed at an oblique angle to the center axes of the cannula and { HEAD ~ the portion } of the optic fiber passing through { TAIL ~ the cannula }
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