What does an expander look like?

I got to thinking this morning over breakfast that maybe there are some people that have never seen an expander or have no idea what it looks like, so this morning whist my Mum was turning it i asked her to take some photos so you could see........and here they are.  When the expander was first fitted the two thick metal bits in the middle virtually touched so you can see how much it has moved and the circular thing in the middle is where Mum pus the key to turn it twice a day.  The expander is held into place by the cement i talked about (that tastes gross) and so far so good and is made of a metal that doesn't rust.

By the way, this mornings turning hurt, like my left front tooth is beginning to ache now but my Mum says it's because it's been given the space to move now so it's going for its life!