A screen, maybe, but you can see through it (6)
I believe the answer is:
grille
'a screen' is the definition.
(screen of bars which can be looked through)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for grille that I've seen before include "Part of an air-cooling system" , "part of the barbecue" , "It affords ventilation" , "Metal lattice" , "Protective lattice" .)