I ran into these in my local WallyWorld for under $8 and thought I would give the a whirl as my thin metal chip box seemed to go up a bit quiick. It would not fit exactly down in the same place due to it being wider. But it is Cast Iron and like a small rectangular version of the one in the bigger GOSM units. Since it sits up a bit there is probably a 1/2" or 5/8" gap to the bottom of the chip box now. After 45 minutes (smoked heavy for a while but kept turning it down and still maintaining 225-230F) I had to check out of curiosity and I can still see unburnt wood through the slots in the top of the chip box.
I guess these are an abosolut keeper for me. Gonna get a second one to have an easy pull one insert one with the door open only once.