This classic novelty is a small, cleverly designed scientific wonder, using the properties of thermodynamics to keep it in constant bobbing motion. Is an awesome gift idea for anyone. Easy assembling. Glass tube w/ non-flammable liquid. Drinking glass and water (Not included). CAUTION: Please note this product is not a toy and is not intended for use by children under age of 8. The glass tube contains methylene chloride and may permanently stain clothing and other surfaces. Do not swallow liquid or allow to come in contact with eyes or skin. Non-flammable. Keep away from flame or other heat sources. WARNING: CHOKING HAZARD-Small parts. Not for children under 3 years.