What is a 710?

{the following is a joke - too funny not to share}

A few days ago I was having some work done at my local garage.
A blonde came in and asked for a seven-hundred-ten.
We all looked at each other and another customer asked, "What is a seven-hundred-ten?"

She replied, "You know, the little piece in the middle of the engine, I have lost it and need a new one."

She replied that she did not know exactly what it was, but this piece had always been there.

The mechanic gave her a piece of paper and a pen and asked her to draw what the piece looked like.

She drew a circle and in the middle of it wrote 710.

He then took her over to another car which had its hood up and asked, "Is there a 710 on this car?"

She pointed and said, "Of course, its right there."

If you're not sure what a 710 is Click Here