Description: - Durable it's highly accurate for measuring range of 0-14 PH, 0.1 PH resolution, measure & display pH result simultaneously with LCD display, reliable and quick reading. - Easy to Use you just remove the protective cap immerse the PH meter electrode in the solution and turn on the PH by the "ON / OFF" switch to be measured. Beats the heck out of trying to see the colors of a litmus strip. - Easy to Calibrate You can simply follow the instruction on the provided packet of solution 4.01 or 6.86, immerse the PH tester in the solution and adjust with the provided screwdriver to dial it in. - Pocket Size It's only 1.76 oz with the size of 5.94*1.22*0.79 inches so that you can put it in your pocket wherever you go outside for PH testing, it also comes with a handy storage case and dedicated screwdriver for calibrating. - This meter is ideal for all water purification applications, thus checking whether your water filter is doing its job right and when to change the filter. - This is a digital meter tester for testing the purity of water, Micron Rating: 0.3, Filter Material: Polypropylene (PP)