Observing the contents in a processing vessel in a hazardous classified location normally requires the use of two Sight Glasses: one for lighting, the other for viewing. The Series REX-100/NW eliminates the expense of an additional port and the expense to install it. The explosion-proof UL-844 and C-UL/CSA C22.2 No. 137 listed Series REX- 100 units and the corresponding Series NW Sight Glass provide glare-free illumination precisely where you want it - at the viewing port.Explosion-proof, UL-844 and C-UL/CSA C22.2 No. 137 listed, electric lighting fixtures are used in hazardous (classified) locations. Lights for single port viewing have been designed to meet the needs of our customers who require lighting and viewing through a single sight glass.Designated the REX-100, this model use high intensity halogen lamps to provide bright, glare-free illumination of the interior of vessels, tanks, hoppers, silos, mixers, and other normally closed containers in hazardous locations requiring explosion-proof equipment. The REX-100 is provided with a highly polished internal reflector which increases the illumination intensity.Notes:1. Sizes NW80 and below are light glasses only and do not allow simultaneous viewing.3. The Series REX-100 and REX-HI-LED may be mounted to virtually any sight glass or sightflow indicator. Contact PAPAILIAS, Inc. for additional information and mounting options.