This easy to install screw assembly replaces the factory powder adjustment screw. The Dillon Factory screw requires a wrench when adjusting the amount of powder to dispense in your powder thrower. The knurled knob is labeled with graduations for orientation and easily allows the user to hand adjust the powder dispenser without the need for tools. Works on Dillon1050, 650, 550, SDB and 900 presses. Dillon Powder Bar is shown only for reference and is not included.