Mine came in today. It took two weeks. I am in the US and it shipped from Hong Kong.
Came with a plastic case, instructions, it's own adjustment tool, and two DRY packs of calibration salts.
The instructions for them are in Chinese but I see the number 250 on each one. I assume mix contents with 250ml of water...But I have my own solutions. It is a single point calibration and the instructions say to adjust on one solution, rinse, and then let set in the 2nd until the reading matches the solution (no adjustments on the 2nd one, just watch and see).
I just calibrated it using 4.0 (solution is 4.01 but this unit only does X.X readings) as I am wanting 5.5 and that is closer to the 4.01 solution than is the 7.01. I see no need to use both solutions when there is only one setting made. Use what is close to the range you are shooting for.
For the cost, damn good buy with free shipping. Now I get to see how long it lasts.
I will say, buying this is cheaper then buying a replacement probe only for my more expensive PH tester. I would buy multiples of these instead of the expensive replacement probes that seem to go bad 6+months out.
It is not as accurate as an X.XX display...but shooting for the exact perfect reading can cause more trouble than what it is worth. I learned to stop chasing PH up and down when mixing a grow or two ago....PH down...to much...PH up...DAMN to much...PH down...
