Spectrum Tube Power Supply is used to lighten up the Spectrum Analyses Tubes through its electrodes Power supply is very safe and reliable. It is manufactured keeping the high standards in mind.There is a knob on the side of the unit, which controls the brightness of the light The tube has a 10cm capillary in the center for observing light wavelengths and is straight form with side electrodes for conductivity. The tube measures 26cm, and is made of glass for transparency and resistance to heat.