A  few  days ago I was having some work done at my local garage. A blonde (I think her name was Lynn) 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 t his car?' She  pointed and said, 'Of course, its right there.'

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