Investigate how air mass is formed and how temperature relates to different types of air masses, Two add-ons at different heights inside tube show how temperature varies with altitude, Set includes one 2, 5"" x 18"" transparent markable tube with integral thermometers on a track two-piece convection chamber tubing funnel smoke generator and Teacher s Guide, American Educational Products have a lead ship time of 21 days, SKU: AMED680