Diffraction Grating Glasses, 500lines/mm, Highly efficient, Single axis holographic diffraction grating lenses separate light from any source into its spectral components for study/analysis, Used with Power Supply/ Spectrum Gas Tubes, Make study of light easy
Spectrum Tubes Deuterium, glass tubes approximately 10-1/4in (260mm) long, central capillary portion approximately 3-1/2in to 4in (90-100mm) long with electrodes sealed at both ends and connected to lead wires protected by metal caps.