Koflo pump calibration columns and calibration cylinders provide an easy method for determining pump flowrate using industry standard graduations of milliliters/minute and gallons/hour. An equal starting point for both graduated scales gives the operator both ml/min. and GPH in one test. High contrast blue lettering enhances readability in all light conditions, and all scales have a protective Mylar lamination to protect against chemical attack. All sizes feature rugged construction using industrial grade machined PVC fittings.