The manufacturer doesn't need it
The buyer doesn't want it
And the user doesn't know that he's using it.
What is it?
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A Riddle a Day -- 78 Logical and Mathematical Puzzles
RandomSome riddles and brainteasers to give you a little something to think about each day!
Day 59 -- Riddle
The manufacturer doesn't need it
The buyer doesn't want it
And the user doesn't know that he's using it.
What is it?