The hub is the foundation of the hexagonal beam. It is made of a very tough
6061 T6 aluminum base plate 3/16 inches thick and two aluminum
magnesium alloy flanges, top and bottom. This gives added strength to the
structure. All U bolts and flange bolts are stainless steel for corrosion
resistant service. Holes are cut with precision laser technology.

The hole in the bottom flange is 1.315 inches (33mm) and a good fit for
most push up masts. However, if you have a larger mast, you can order as
an option for a nominal fee instead of the regular flange, a larger bottom
flange as shown below that will accommodate a mast of 1.9 inches (48mm).
The Base Plate
Bottom view
No fiddling with adjustments to get the
center post plumbed or centered correctly
with this baseplate. Just slip it in and you're
done. This simple but rugged design is
tried and proven to be completely reliable
and trouble free. No patent, it's too simple
for that.
Specializing in Hexagonal Beams for the DX Enthusiast
Your 2 inch mast will NOT fit into this large flange but you might want to
consider use of a Schedule 80  pipe made of 6061-T6 aluminum that is 1.9
inches O.D. with wall thickness of  0.2 inches. Find it at places like Online
Metals.

See ways to couple the base plate to your mast here.
Click to enlarge
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