Workers in this unit group operate furnaces and kilns in the manufacture of glass and ceramics products. Their functions include: operating a glass-making furnace; operating a glass-annealing furnace to prevent or remove internal stresses; operating a tempering furnace to toughen glass; operating kiln to bake pottery and porcelain ware or to bake ware again to fix glazing and decoration; operating kiln to bake bricks and tiles; performing related tasks.