Nanotechnology is changing the world. Aerogel, also known as 'Frozen Smoke', is a truly space-age material. Silica aerogel contains particles of 2-5 nm in diameter. It is 99% air, but exhibits extraordinary insulation and structural properties, and therefore holds 15 entries in the Guinness Book of Records. You can light a gas torch on one side and it won't get hot enough to light a match sitting on the other side! Some chipping around edges is normal. Classic Silica™ aerogel disc, 27 mm diameter x 7 mm height. Note: While this material is amazing, the properties that make it amazing also make it inherently fragile. It is intended for adult handling. Handling instructions included.