A kettle grill is a spherical charcoal grill that takes its name from the shape. The design was pioneered by the grilling company Weber in 1951, and there are other companies trying to seize the market share. Its design includes a round lid, a steel cooking grate, and two sets of vents—bottom vents beneath the charcoal firebox, and top vents in the lid. The picture shows the prototyping process of the grill grate with SLA 3D printing technology.