Safety feature of sandwich counter (7)
I believe the answer is:
rollbar
'safety feature' is the definition.
The definition suggests a singular noun which matches the answer.
'sandwich counter' is the wordplay.
'sandwich' becomes 'roll' (I am not sure about this - if you are sure you should believe this answer much more).
'counter' becomes 'bar' (bar is a kind of counter).
'roll'+'bar'='ROLLBAR'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for rollbar that I've seen before include "Protection if car overturns" , "Sports car safety device" , "Safety frame used on motor sport vehicles" , "Maybe one resisting turnover" , "protection for drivers" .)