A few questions on the Zodiac GMT Chronograph

[Frank]

Hi,
On the "My Watches"  page there is a Zodiac GMT Chronograph watch  (first row, last picture on the right)   I have a watch that is identical to it  with the red/blue bezel.  The front doesn't say anything but "Zodiac GMT"and "Swiss"below just like the one in the picture The back of the watch is smooth and doesn't have any markings except a small half circle (done in four lines) at the edge.  I would love to see the movement, but I don't have a clue how to open this watch.  It looks like it may need a special tool. I would like to know if is an Automatic or what type of movement it is, how many Jewels and approximate age?    I don't know if this the right section for this, but thanks for any information.   
Frank

[Butch]

Mine is a snap back case and all you need is a watchmaker's knife to pop mine off. IF I remember correctly, this is basically a Val Joux 72 movement in it.

Butch

[Frank]

Thank you. 
Frank