This short-range Hydrion MicroFine pH paper measures pH solutions in the slightly acid, neutral, and alkaline range of 6.0-9.5 and offers clear bright single color matches at every .5 interval in the acid to neutral range and .2 or .3 interval in the alkaline range. Hydrion MicroFine pH papers are ideally suited to testing minute amounts of solution, only requiring 0.0001 mL for an accurate measurement. With a width of 5/32 in in, Microfine pH paper also fit easily into small tubes.