Exodus 27:3-7

Also you shall make its pans to receive its ashes, and its shovels and its basins and its forks and its firepans; you shall make all its utensils of bronze. You shall make a grate for it, a network of bronze; and on the network you shall make four bronze rings at its four corners. You shall put it under the rim of the altar beneath, that the network may be midway up the altar. And you shall make poles for the altar, poles of acacia wood, and overlay them with bronze. The poles shall be put in the rings, and the poles shall be on the two sides of the altar to bear it.