The B94GU emergency ballast works in conjunction with an AC ballast to convert new or existing fluorescent fixtures into emergency lighting. The emergency ballast consists of a high temperature nickel cadmium battery, charger and electronic circuitry in one compact red case. The B94GU can be used with one 18 42 W 4 pin twin, quad or triple twin tube compact. It is also compatible with most one , two , three and four lamp electronic, standard, energy saving and dimming AC ballasts. If used in an emergency only fixture, no AC ballast is necessary. The B94GU is suitable for indoor and damp locations and for sealed & gasketed fixtures. It is not suitable for air handling heated air outlets or wet or hazardous locations. For information about specific lamp and ballast compatibility, please call the factory.