Flit gun

Below the front of the pneumatic tube hangs a cylindrical container which acts as a reservoir for liquid insecticide, this reservoir being set at 90 degrees to the pneumatic tube.

In early versions, the reservoir is permanently secured to the pump and equipped with a removable, gasketed screw cap for filling.

In later, improved versions, the insecticide reservoir is secured to the pump with a coarse screw fitting and a seal of cork composite or gasket paper, so that it can readily be unscrewed for filling.

A venturi tube extends from the pump cylinder downward into the reservoir and the upper end of the venturi is positioned in front of a nozzle on the air pump.

When a jet of high-velocity air exits the pump and streams across end of the venturi tube, it lowers the pressure in the venturi (Venturi effect and Bernoulli's principle), drawing insecticide upward from the reservoir, which then atomizes the liquid as it is entrained in the air jet (it is an atomizer nozzle).