Einstein Experiment TEST TUBE Glowing Putty. Einstein's test tubes are exciting mini experiments that achieve a big wow effect with little effort! In this test tube, you'll discover the glow-in-the-dark putty: It looks inconspicuous in daylight, but in the dark, it unfolds its full magic! Simply hold the putty briefly under a lamp to charge it with light, and marvel at the cool glow-in-the-dark effects in the evening. This makes experimenting really fun, and you'll become a little Einstein in no time! The experiment instructions are included with the product - or you can simply download them here and get started right away. Ages: 8+ years. Warning! Not suitable for children under 3 years. Choking hazard due to small parts.