Review on 🌈 Discover Stunning Rainbow Effects with Rainbow Symphony Paddles Diffraction Gratings by Eric Pavelko

I've used this with spectrometers and a flashlight. This helped students understand that white light is a spectrum of colors. It's cheaper than light bulbs. I want it to be plastic pens rather than paper/cardboard. Although it will take time. Great price and great product. I wish I could afford more for students but one set worked.