Shown above in a bottom view (click to enlarge), you can see also the suspension beam and one of the pivots. The linkage arm sticking up out of the top of the picture normally faces downward and it allows the collector to be rotated to face the sun. One of the fluid inlet/outlet spigots can be seen on the end.
SUNTUF corrugated polycarbonate glazing made by Palram Americas. Here is a view of the sealed flat plate collector with the Suntuf in place. Suntuf is crystal clear and very tough although the sheet polycarbonate it is made from is quite thin (0.75mm or 0.030") and it seems flippy until it is fastened in place.
You can see the "wings" on both sides. I found the Suntuff hard to cut and did not bother to make the two longitudiunal cuts that I would have had to make to have it fit the collector exactly. The "wings" serve no purpose but they do not affect the function either. It was just easier that way and I was worried about cracking the sheet while cutting.
The insulated flat plate collector is now complete and awaiting further tests.