The straight rod assembly had the box extending past the arm cuff.My goal was to make the unit more compact for transporting and for use in the field.My solution instead of using the extension I mounted a V clip underneath the arm cuff.A very simple operation two small holes drilled,a V clip and a couple of screwsThis makes the balance and dimensions more like the GT.The extension still has a V clip and can be mounted,I probably could have sawed part of the rod assembly off and came up with a better compromise with balance and bulk,but for me this should work fine.One photo is one with the rod Assembly in past the set holes for transport.