[Ken,
I was looking at these also. How do they work?
If I drill a hole in a 4" diameter acrylic tube and put these in and then use a 3/4" threaded fitting, does placing the fitting in, compress the Tee eliminator against the acrylic and prevent a leak?
Is this what you use on your Kalk reactors and other diy projects?
Thanks,
-soji]