Item made once only (3-3)
I believe the answer is:
one-off
'item made once only' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for one-off that I've seen before include "Something unique" , "Made as single article, not repeated" , "Not repeated, being a single event or object" , "Not repeated or reproduced, a single thing" , "Made or done as a single thing, not repeated" .)