38mm dark green spray applicators used to apply liquid fertilisers or foliar sprays.
These tubes suck up the liquid fertiliser or foliar sprays when the water from a hose travels past the bottle.
How does the venturi effect work? When fluid flowing through a tube is forced through a narrow section, a velocity increase is the result. This is similar to how water’s velocity increase when you place your thumb over the end of a garden hose to create a high-pressure spray.