TOOGOO(R)Digital PH Meter Tester Water LCD Monitor Aquarium Pen Type Measuring pH Range: 0.0 - 14.0 pH.&gt;Resolution: 0.1 pH.&gt;Size: 15.2cm x 2.8cm x 1.5cm.&gt;Case Size: 17.7cm x 6.8cm x 3cm&gt;Ideal for measuring the pH (acidity or alkalinity) of a liquid