Normal sizes are 300mm*8,400mm*16,500mm*24,600mm*24,600mm*48. receive customized size material:aluminium 1.Powder coated in face.2.Plastic adjustable blades.3.Normal sizes are 300mm*8,400mm*16,500mm*24,600mm*24,600mm*48.4.Numbers of slots can be 48,36,24,12,6 and so on. aluminium square celling Swirl air Diffuser air grill SW-B