For gas, maybe, but smoke can get through it (4)
I believe the answer is:
pipe
'for gas maybe but smoke' is the definition.
I can't tell whether this defines the answer.
'get through it' is the wordplay.
'get' is a charade indicator (letters next to each other).
'through' becomes 'pip' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
'pip' put next to 'e' is 'PIPE'.
'can' is the link.
Can you help me to learn more?
(Other definitions for pipe that I've seen before include "chanter" , "Fluid or gas transporter" , "Utter shrilly; wine cask" , "Tobacco is smoked in it" , "Long tube" .)