A1) 48 Diameter x H30 A2) 48 Diameter x H30 with 1-24" center extension A3) 48 Diameter x H30 with 2-18" center extensions B1) 54 Diameter x H30 B2) 54 Diameter x H30 with 1-24" center extension B3) 54 Diameter x H30 with 2-18" center extensions C1) 60 Diameter x H30 C2) 60 Diameter x H30 with 1-24" center extension C3) 60 Diameter x H30 with 2-18" center extensions D1) 72 Diameter x H30 No extensions available E1) 84 Diameter x H30 No extensions available