Just measured it, and the base is about 14" diameter, and overall is height is about 19.5".

I use plastic 20mm pyramids, as I use it for deburring and finishing smallish aluminium parts. A 5Kg bag of the pyramids fills it up to around the mid level of the bowl.
I normally throw in what parts I'm doing, and let it rumble away for an hour, which seems to be enough to flatten all the surfaces and knock the burrs off.

I do also have some ceramic prisms, but I've never had a reason to try them.


However, it may be worth considering bead blasting, as I think it gives a nicer finish on flat surfaces, provided you get the technique good. It does however take more time, and you need good extraction/filtering, as you really don't want to be breathing sand or glass dust.