JessEm router fences question

I'm looking to upgrade my router fence and was hoping someone could help me understand the difference between the JessEm Rout-R-Fence and the JessEm Mast-R-Fence II.



Mostly I would like to know if the Mast-R-Fence II is made of heavier components.



Thanks,

Richard

(b6f)

JessEm router fences question