Just measured mine (in case there's more than one version almost the same).
GG is 100 x 75mm opening.
Overall it's 155 x 101mm (141mm without the two "tabs").
The hood is 118 x 83 x 88 by itself.
But compared to the pictures on that fleabay listing, mine does NOT have those two silver levers top and bottom, no tabs top/bottom centre, nor the cutout on the end where it goes under.
I can't quite tell from the pics, but are they just a smaller version of a graflok/spring back?