Contains 1xinsect eye glasses (segments and colours light like insect vision), 1 x parabolic convex mirror (balloons out images in its reflection), 1 x diffraction glasses (splits white light up into the colours that make it up like a prism, 1 x icelandic spar (exhibits birefringence essentially duplicating whatever is viewed through it). Kit is really fun for kids to learn more about light and colour in a playful way.. Recommended donation is £1.05 Cost to replace is £13.5