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
Tuning Fork Octave, 8Pk C (256Hz) - C (512Hz), Steel Tuning Forks For Physics Experiments, May Be +/- 5% Of Stated Frequency, Includes: (8) Tuning Forks, Nickel-Plated, Plain Shanks, With Frequency Marked, C (256), D (288), E (320), F (341), G (384), A (426), B (480), C (512)