It is a bit more expensive than a stock pot thumper, but it is a pressure vessel and you can mount a lot of weight on top of it if you need to.
30 litre keg
Essex flange in the top for the vapour inlet
1 compression bulkhead in the base for a drain
Another for an overflow if you need one
4 brackets and 200 mm coach bolts for adjustable legs
1 or two gate valves.
If it is just a basic thumper going to a product condenser though you can make one from a cheap ebay stock pot.
There are always different ways to do things just please don't use a glass thumper without a lot of carefull thought. I have never consideded it a good idea.
You can even do copper thumpers but they tend to be expensive options. Even more than the keg. I do have one that will get remodeled for my own personal stil. I am going to remove the water seal and fit a 4" triclamp instead.
I was never really happy with the column on it, so it is going back to the pot still as a flavour thumper just before the product condenser.