What's possibly needed to see small details? (5)
I believe the answer is:
specs
I believe this clue is a double definition.
'what's possibly needed to see' is the first definition.
(spectacles)
'small details?' is the second definition.
(Other definitions for specs that I've seen before include "you can see right through them" , "Glasses (abbr)" , "Instructions" , "what builders are doing?" , "Detailed plan" .)