Helps to prevent flux from eating up the insulation and bricks in your gas forge. Dimensions are 11 3/4" Long X 4" Wide X .5" thick. Will fit in most forges & can be cut to fit. Flux will eat up the refractory floor of a gas forge. The ceramic welding brick prevents this damage. Buy a pound of anhydrous borax and you can begin to get those welds to stick. This is one investment that all owners of gas forges should make. It will save you from having to replace your forge floor.
I've tried other things but nothing seems to work as well as this ceramic brick. Used in conjunction with anhydrous borax, you won't need as much grocery store borax. You won't have your grocery store borax, swell up and fall off. Anhydrous borax melts on contact, non fluff, no mess.