I have had two Explorer XS's and two Ex 11's over the last seven years. I do remember my first XS having a square cut upper rod. I was digging through my excess odds and ends and I came across an Explorer upper rod. The end where it goes into the control box is square cut with a ridge on one side. Can anyone tell me what Explorer this rod belongs to? I sort of remember putting this rod away when I got a Sunray probe, but for the life of me, I can't remember if it belongs to the XS or EX 11. Thanks. R.L.