Replacement bulb for Fisher Scientific agglutination viewer. 5 watt xenon bulb. Replacement for Fisher catalog 22-363-561. Simply unscrew black top of agglutination viewer lamp and pull out wedge bulb. Push new bulb in and screw black top back on. Note:  Gloves are required when replacing new bulb so that oil from your hand will not damage bulb. Unplug unit from power source before changing bulb.