1 PCS Spectroscope & 1 PCS 5m pH Test Paper Ever wonder how do we know the composition of suns and stars far in the universe? The answer is spectrometer, the amazing equipment that can analyze light spectrum from any light source. You have read it in text books, now you can have it in your hand and observe Sun's emission spectrum yourself! The spectroscope is made of optical glass. The composite prism and converging lens are installed in the vertical tube. Hold the spectroscope tube, the slit facing the light, a parallel beam is generated from the slit and converging lens. When the parallel beam pass through the prism, the dispersion spectrum can be directly observed. If the light source is fluorescent light, against the background of the continuous spectrum, one can see the line spectra of mercury (three straight lines). When use it for sun light observation, please use sun's reflected light from a mirror (Do not directly face the sun). This product can be used for a variety of light spectrum analysis. It is a high-resolution, simple, and economical product for hobbyist, amateur scientists, student lab and science fair projects. Color: Photo Color Material: plastic+paper 5m pH Test Paper: Scale Reads From 1 to 14: 1 - 3 indicates a very acidic substance 4 - 6 indicates an acidic substance 7 indicates neutral 8 - 11 indicates alkalinity 12 - 14 indicates a very high level of alkalinity PH 1-14 color chart in each pack The test strip color changes must be matched with the pH scale color chart within about 15 seconds Instruction: Simply press the testing strip to the object or liquid you are testing. Half second later, take out the paper and using the color chart included, compare the color change of the paper to find out the acidity level of your testing subject. Can not indicate the Acid or alkali solution when its density was lower than 0.01%. Keep dry for the rest paper. Paper length: 5m/16ft Spectroscope: 100% brand new and high quality Size: 10x2.4x2cm/3.94x0.94x0.79 inch Package Contents: 1 x Spectroscope 1 x 5m pH Test Paper Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.