I believe some people have had problems getting a 5500W ripple element through the 1.5" adapter.
Let me make one suggestion here:
I will agree with this statement.
I purchased the Brewers Hardware 2" Element Adapter
for use in my boil kettle. I also got a 5500W ULWD Ripple element. I was very bummed to find out that I was unable to fit the ripple element into the adapter. So I ended up having to guy a straight style element. I still love the adapter. Just a small tradeoff. I would be willing to bet it would fit into the adapter without the enclosure
however. So I would recommend that, from my experience, the enclosed adapter is definitely worth the money in that everything is enclosed and there's even a grounding screw provided Right from the get go! The 2" provides lots of space to install the element, but if you do go with the enclosed adapter, a straight element is required.