New Pentair FNS+ 48 D.E. Filter Plumbing (Sightglass??)

I just received my new Pentair FNS+ 48 D.E. filter in the mail, along with the high-flow MPV and a 'sightglass kit'.

Problem is, this "sightglass" is basically a clear piece of plastic that has threads on one end, and a big hole at the other. I'm sure you veterans know exactly what I'm talking about, but that makes one of us. ;)

I've seen numerous sightglass before, but they were all small (maybe 1" diameter) and they screwed into the MPV, and they were closed (like a cup). This is closer to 2" diameter and wide open, if I screwed it into anything (which I don't even know where to put it, the MPV doesn't seem to have a place to screw it into) the water would just come rushing right out.

So, any ideas?

For example, this is what I expected...

http://img813.imageshack.us/img813/4...glaspected.jpg

And this is what I received...

http://img577.imageshack.us/img577/6...ssreceived.jpg

Am I missing something?

Well, on some filters Pentair began replacing true sight glasses with lengths of clear PVC -- but they aren't interchangeable.

If you've got a place to screw-in a sight glass, you'll need a sight glass.

Ben