The ?Understanding Asthma chart takes a look at the causes, symptoms, risk factors and treatments for asthma. The anatomy of airways and gas exchange is graphically depicted, along with a peak flow chart. Images of normal and asthmatic bronchioles are shown for comparison in the asthma attack section. Heavy gauge 3ml lamination with sealed edges and two metal eyelets for hanging makes chart highly durable. Write-on/wipe-off with dry erase marker (not included).