ORP stands for Oxidation-Reduction Potential
In practical terms, it is a measurement to oxidize contaminants.
In short, it measures the quality of the water.

If the ORP test result is negative number; it means that the water is
free of rust, fresh, and anti-aging.
Only KANGEN water has the negative number result ( -387 ).

If the ORP test result is positive number; it means that the water is rusty, spoiled, decomposing, and aging.