Apera Instruments 201T-F All-in-one pH Electrode, ATC, BNC/RCA Connector, Polycarbonate Body AI1302

Apera Instruments AI101G GroStar Series GS1 pH Pen Tester Kit with Replaceable Double-Junction pH Probe for Hydroponics Water Quality Testing, Gen II

Apera Instruments AI102G GroStar Series GS2 Soil pH Pen Tester Kit for Direct Soil Test and Nutrient Solutions Test with Replaceable Swiss Spear pH Probe, Gen II

Apera Instruments AI103G GroStar Series GS3 EC/500ppm/700ppm Pen Tester Kit with Replaceable Titanium EC Probe for Hydroponics Water Quality Testing, Gen II

Apera Instruments AI104G GroStar Series GS4 pH/EC/500ppm/700ppm Combo 5-in-1 Pen Tester Kit with Replaceable Double-Junction pH/EC Probe for Hydroponics Water Quality Testing, Gen II

APERA INSTRUMENTS AI209 Value Series PH20 Waterproof pH Tester Kit, ±0.1 pH Accuracy

APERA INSTRUMENTS AI209-T Value Series PH20 pH Tester Combo Kit, including the Maintenance Set, and a CalPod Solution Holder for Easy Calibration

Apera Instruments AI213 Value Series TDS20 Waterproof TDS Pocket Tester kit, Accuracy: ±1% F.S, 2-Point Auto. Calibration