HI 98127 - pH tester with replaceable electrode.
Features:
Dual-level LCD, battery level indicator, replaceable pH electrode cartridge, instability indicator, automatic shut-off and automatic calibration all in a floating, waterproof casing. Specifications:

• Range pH: -2.0 to 16.0
• Range temperature: -5.0 do 60.0 °C
Resolution pH: 0.1
• Resolution temperature: 0.1°C/ 23.0 to 140.0°F
• Accuracy pH: ?0.1
• Accuracy temperature: ?0.5 °C
• pH Calibration: automatic, at 1 or 2 points with 2 sets of memorized buffers (pH 4.01 / 7.01 / 10.01 or pH 4.01 / 6.86 / 9.18)
• Sonda pH: HI 73127
• Battery Type / Life: 4 x 1.5V with BEPS / approx. 300 hours of continuous use; auto-off after 8 minutes of non-use
• Wymiary: 163 x 40 x 26 mm