... tobacoo,to chage the molecular structure of tobacoo to nicotine,tar,formaldehyde,hydrogen cyanide,polycyclic aromatic hydrocarbons(carcinogenic substances )ans ... crystals,retained ash,thus achieve the purpose of reducing tar harm reduction.It was determined that ,this card ... be greatly reuced,if ther insertion time increases,the nicotine to,tar and other harmful substances content continued to decline ...