Big Green EGG Fire Lump Grate - Various EGGsReplacement Lump Grate in Fire Box for Big Green EGG Grills These lump grates are found near the bottom of the fire box. The gates are heavy duty cast iron. The grates hold the lump. The holes allow air to pass and ash to fall through for consistent burns. The Grates are marked which side is up in the fire box. Check out Kick Ash Baskets for a modern day alternative to the lump grate. Complete Warranty details can be found here Big Green Egg Warranty.