Light Boxes enable the safety signs to be back-lit for greater visibility on dull days or at night.  They also provide local illumination to ensure that the shower and/or eyebath/facewash operating mechanisms are easy to see at all times as recommended in the ANSI Standard Z358.1-2004.
For Non-Flameproof models the optional Light Box is fitted with two lights inside, whereas on Zone 1 & 2 models a single bulkhead type light is fitted. Other types of light are available such as fluorescent and MBF/U (Mercury) lights should these be preferred.