Abstract: A dosing device for a pneumatic delivery system particularly for powdery granular and similar coarse and fine grain materials comprises a first delivery tube defining a first conduit for the coarse dosing having a coarse dosing discharge. A second delivery tube defining a second conduit for fine dosing has a fine dosing discharge and it communicates with the first delivery tube through an intermediate housing having a screen therein for the passage of the fines from the coarse dosing conduit into the fine dosing conduit. The material is delivered by a pneumatic delivery tube into the coarse dosing conduit and it may operate to discharge the coarse feeding of material into a weighing tank. When the coarse conduit is shut off when the amount of weighted material approaches the desired value a feed screw in the fine conduit delivers an additional amount of material into the weighing receptacle.