For concentration of trace amounts of analyte in organic solvent.Lower body of flask has a hemispherical shape to afford continuous flow of heavier fractions to concentrator tube during reflux.Top joint is a 24/40 outer while the lower joint is a 19/22 inner. ● Material:Borosilicate glass ● Color:Clear ● Heavy Duty Reusable ● Top outer joint size:24/40 ● Lower innern joint size:19/22 ● Joint size 24/40:24 refers to joint diameter,40 refers to joint height,other specifications and so forth ● Accessory:J3526-01 Joint Clips 19/22,J3526-03 Joint Clips 24/40 ● Matched with C3865 Graduated Concentrator Tube