🔍 Roto Flo H19937 0001 Polystyrene Indicator by Bel Art Review

Works perfectly. The round body measures 1 inch by 3/8 inch. Clear and compact flow monitor. There should be 3 or 4 for $30. If you can't do one, what will you do.

Not very air sensitive. I measured 2.5-3 l/min before the gauge started rotating. The brochure that accompanies the device states that a minimum of 2 l/min is required for use with air. You must state this in the product description. The specification of 0.5 l/min applies to a liquid, most likely water.

As clearly stated in the product description, the internal flow passage of all three different sized items is the same - 5mm. I wanted 1 /2" and the only thing that measures 1/2" is the flange on the 5mm fitting. If you're counting on a full 1/2" flow, that will reduce the flow! As it turns out, this was an acceptable (albeit undesirable) reduction, so I left it installed. It works well And there was nothing tricky about it, seller or description. I just skipped it and want to call it for…