... in plants where the explosive mixtures of IIA Class, TI, T2, T3 or T4 are present. ExdIIBT4 - safe for use in ... plants where the explosive mixtures of IIB Class, TI, T2, T3 or T4 are present. ExdIICT4 - safe for use in ... plants where the explosive mixtures of IIC Class, TI, T2, T3 or T4 are present. Available type1:Frame: H80 to ...