Horizon spf 20a

Could someone guide me on this one,when the specifications are set to 73mm-160mm on the SPF 20A unit,what is the reference,between centers of the staples or edge to edge,I need a clear guidance.

 

i'm not sure what your asking, 73mm would be the distance between staples on a small book and 160mm would be the distance on a large book, for example a 280 mm book would have 50mm from the edge of sheet to the staple top and bottom and 155 mm between, you just center so the staple heads do not impede the jogging. hope that helps.