ComputeBuffer used for Graphics.DrawProceduralIndirect, ComputeShader.DispatchIndirect or Graphics.DrawMeshInstancedIndirect arguments.
Buffer size has to be at least 12 bytes. Underlying DX11 unordered access view format will be R32_UINT, and shader resource view format will be R32 typeless.
Additional resources: ComputeBuffer, ComputeShader, Material.SetBuffer, ComputeBuffer.CopyCount.