Rotopax 4 Gallon Dimension Request

I'm looking for the total space occupied by a 4 gallon rotopax from the mount to the very end (probably at the handle?). So if anyone has a 4 gallon rotopax, the real life measurement would be greatly appreciated! I've been planning on adding a 4gal pack to my warn tire carrier between the back of the carrier and the rear window

Thanks!