Enclosed crawfish pot burner

I saw some pictures of a crawfish boil in Eunice awhile back and they were using a normal crawfish pot. But the actual burner that the pot sat in was all enclosed so that the sides also heated up. It was round just like the pot, but with a hole in the middle where the pot went. This was my first time seeing this, has anyone ever seen this or know where its sold. If I had to guess, im sure somebody makes in in Eunice, Crowley or Ville Platte TIA