44The front rail has a unusual extruded shape that pulls the fence in square with the fence when the camlock lever locks it into place. The fence arm itself measures 60mm high and 430mm from the clamping arm, so it should reach across the distance of most tables. The rear rail is there to support the back ledge of the fence arm, so table width is not critical.
The front rail is graduated in both imperial and metric sizes. The viewing lens on the fence arm itself is magnified, which makes it easier to line the fence accurately against the graduations.
It may require some adjustment to get the measurements reading accurately, and its clamp the fence arm to the front rail and then lay the whole assembly on to the bandsaw table to make where to drill the holes. The great news is that the holes on the front rail are elongated so you have to be basically correct, but can finetune it by loosening the bolts and sliding the fence along the holes until it lines up correctly.