This set contains 28 images as shown on preview pages, wich includes 14 color images and 14 black line versions. Images saved at 300 dpi in png files.Check out these related clipart sets:Light - ScienceLight (Radiant Energy)Lenses and MirrorsLenses and Mirrors - TechnologyTransparent, Translucent, OpaqueSound - ScienceI also have quite a complete selection of physics clipart in the following bundle:Forms of Energy Mega Bundle.Human Body Systems - Bundle 1Human Body Systems - Bundle 2Five Senses