Attributes . Class I, Division 1 and 2, Groups A, B, C, and D: Class II, Division 1 and 2, Groups E, F, and G: Class III, Division 1 and 2: Temperature Code T2D, T3B, T4A or T6. CSA type 4, Class I, Zone 1 and 2, Groups IIA, IIB and IIC. . Names