I have Truncheon and it is kinda not to my liking. There is no calibration possible. It reads 299 as 0,2, 399 as 0,3... It measures only few seconds after submerging, than it just stops. When I followed their “cleaning and calibration” protocol ended up reading nonsense in EC 2,77. So this solution as well as cleaning kit is useless. It is just dish soap and tooth brusher for pH probes and ciff and leather for EC meter. You can use your finger instead, it is written on the truncheon on the back side, so completely waste of money. On the other hand, I had their pH pen but sold it after buying soil pH pen. This I love the most. If I could I would not buy truncheon but rather look for something, which is easy to calibrate and easy to buy LIQUID calibration solution as well. Now that truncheon is reading 2,4 instead of 2,8 and you can do nothing about that and if it is your only one meter, it can lead to troubles. But its just my opinion.