I am getting rid of my insulating firebox I used for my competition cooker. I believe it is 3/16" double walled with 1" mineral wool board in it as insulation. It is fitted with a sliding camper on the front and two valve for a BBQ Guru system. It has an expanded metal charcoal basket on the inside. It is mounted on casters for easy movement. It is perfect to weld onto a tank conversion or any vertical cabinet cooker. If you are interested make me an offer .