The variable area flow meter is used to measure the flow rate of liquids and gases  and consists of vertically tapered tube through which the fluid to be measured is passed from smaller end of the taper and up to the larger end.  The fluid flow raises an indicator f(float) in the tapered tube increasing the area for passage of the fluid. The indicator moves up or down is in proportional to the fluid flow rate.  By varying the taper of the tube, the mass of the float, the length of the tube, different flow ranges can be calibrated. The standard turn-down ratio of this flow meter is about 10-to-1. These parts are for F-410N acrylic liquid flowmeter accessories.