GPH-DOS - pH buffer solution, ready to use in dosing bottle

Technical pH buffer in the practical dosing bottle.
The "measuring chamber" is filled by simply pressing the bottle, the pH electrode can be immersed directly into it.
After the adjustment/calibration process, the contents of the measuring chamber can be disposed of, so that unadulterated calibration solution is always available. The chamber can be filled at least 10 times, max. 15 times.