Ozone safe Blow-Hard® Dust Remover provides powerful blasts of triple filtered air for cleaning a wide variety of laboratory equipment which could be damaged by wiping, such as microscopes. A handy extension tube (included) effectively penetrates hard-to-reach places for thorough dust removal. Blow-Hard® O.S. Extra™ Dust Remover is defined as non-flammable (tetrafluoroethane). Warning instructions for safe use are printed on the can. No Air Shipment.