Skippy,
All I can say is the pointer was facing uppermost 9base up)and I thought it was a SUSAT but we called the TRILUX because it was easier, as the illuminated post could light up brighter and you could adjust its intensity.
Because of so much time going past, and so many trials of various kit Peter and his colleagues or whoever it was sent them to us in those first few years, made us undertake in those early days I found the Trilux SUSAT if that is its correct name the best. I had it on the border on the first tour, so assumed unless I had another on the second tour can't help there.........memory fade
We were even issued secondhand US bodyarmour direct from Vietnam, dirty round the collar which we promply cut off and stitched the top round covered in Ace of Spades and a guys name etc, we were the testers for everybody