An ultraviolet unit being wheeled into the embarkation room.
An ultraviolet unit is a unit which holds approximately 12-15 ultraviolet fluorescent tubes.
Samantha Carter ordered that these units be brought into the embarkation room when O'Neill was pinned to the wall by the Orb. (SG1: "Message in a Bottle")
IRL such units, also called "black light lamps" used in hospitals to disinfection/sterilization of rooms and halls, because UV light kills most bacteria and some viruses.
Also they can be used to provide artificial tanning in areas where the sunny days are few and humans can't obtain natural Vitamin D, which produced in human skin under the Sun's UV radiation.