Comes in (6)
I believe the answer is:
enters
'comes in' is the definition.
('enter' can be a synonym of 'come in')
This is the entire clue.
(Other definitions for enters that I've seen before include "Registers for a competition, say" , "Comes in" , "Inserts" , "Goes in or records in book" , "Records, in a diary say" .)