Extech Instruments PH 100 ExStik Ph Meter PH from 0-14.00 pH New open Box 723434132528 | eBay
THRENS Water Tester Water Quality Tester Digital pH Meter PH EC TDS Salinity Temp 5 in 1 Pen Meter Precise LCD Digital Multifunctional Water Quality Monitor Test for Aquarium Hydroponics - Walmart.com
0.00 to 14.00, Auto Temp Compensation, pH 700 Benchtop Meter - 6CAU7|WD-35419-10 - Grainger