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 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. It is not suitable for air handling heated air outlets or wet or hazardous locations. Universal input voltage; One-lamp emergency illumination for 4-pin fluorescent lamps (without integral starter); Suitable for low mercury lamps. Replaces B94G & B94CG