Identical to 7531-10 with the exception that the nozzle is replaced by a sintered glass filter, porosity A (145-175 microns). Used in determination of Acrolein: 4-Hexylresorcinol Method #1. Bottle has encircling graduations from 0 to 25mL or 0 to 30mL in 5mL divisions. Inlet/ outlet are 7mm O.D. For 0-25mL bottle only, 7531-02. For 0-30mL bottle only, order 7531-04.