The classic demonstration of spectral lines. This Deuterium Spectrum tube will acquaint students with the spectra of this gas in its pure form and also for demonstrating wavelength. The gas has a distinctive set of spectral lines when energized and viewed through a spectroscope. A spectrum tube power supply (not included) is required to energize the tubes. The glass tube is 25cm long with the capillary portion about 10cm long. An electrode is sealed in each end and attached to a metal end cap with a loop for convenient hookup to wire connections. Includes an activity guide.