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 others. I figured this product would be the answer because I just couldn't find a flow meter at a reasonable price well over 1/4". I got scammed (again, not the seller's fault) so hopefully not.
80 Pieces Water Test Litmus Strips Litmus ph Paper Soil Acidity Meter Liquid pH Tester 1-14
10 Review
TDS water quality tester - TDS water hardness meter (portable digital salt meter for water analysis)
9 Review
Portable digital multimeter with sound continuity and thermocouple (electric tester) LTX DT-838
7 Review
π― Honey Refractometer with Automatic Temperature Compensation (ATC) - Tiaoyeer Moisture, Brix, and Baume Refractometer for Honey, 58-90% Brix Scale Range - Honey Moisture Tester
31 Review