Seiko 7A38 - by the numbers

You'll sometimes see wives / girfriends (i.e. SWMBO's) refered to on other watch forums as 'the 710', as a kind of  'secret code'. 

This is in (derogatory) reference to a long standing 'Blonde' joke, which goes something like this:

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.

On this forum, if you see '710', it'll be more likely that someone is referring to the green plastic insulator (a.k.a circuit block spacer) ....

Seiko p/n 4408.710

After all that's what's moulded into the edge of it - 710