Good filter cartridge, poor quality TDS tester
"The water filter cartridge itself is just like always — it works well and I have no complaints about the filtration quality. I’ve used this type before and it performs as expected. However, the included TDS tester is very low quality. The battery does not stay in place and keeps popping out, which makes the tester unreliable and frustrating to use. Because of this issue, I can’t properly trust the readings. Overall, the filter cartridge is good, but the TDS tester needs better build quality."