This is a 1970's  Certina Automatic Mid Size Gents Sports Watch. We think this is a rather rare model as we can't find a Certina Watch remotely resembling this.
 
The Watch is in good condition, the steel case is signed Certina on the back, there are a few scratches but nothing major, the black dial shows no sign of wear at all, the back of the case is see through and the movement is visible.
Inside the case is a 17 Jewel Lever Swiss Automatic Movement signed Certina
Cosmetically overall in good condition and running well.