I used that same box from them. Works great for a Kal clone. The bottom plate comes with a gasket. I used JB weld to seal it up instead of gasket. I actually used it as the top and cut it from my heat sink. Good to see them back in stock, they have been OOS for a while. Just a FYI, their regular store is much cheaper for stuff, better shipping rates. http://www.pioneerbreaker.com/
btw, mine came without the backplate, they sent one free of charge.