The P-2270-16 is a Wavelength & Spectrum Demonstrator, which shows how colors affect wavelengths and learn why red is chosen for stop, in traffic signals.

With a hand held spectroscope the spectrum produced by various colors can be studied. Consists of a metal tube 12 inch (300mm) long x 1.18 inch(30mm) dia, mounted on a 3.9 inch (97mm) dia metal base. 11 different color and wavelengths LEDs are mounted in the metal tube. Color and wavelengths are marked on the tube. Operates on 5V dc, adaptor for use with 110v provided. A nice equipment to have in the classroom to catch student's attention. Spectroscope not included.