Although I have not confirmed how many of 100 are defective, two defective items appeared just by replacing one set of tires (four). One seemed to be bad in accuracy and the air came out vigorously. Another thing is that my head is crooked and I do not feel like using it.
As we use tires for trucks, we only use them for heat resistance, so we use a lot. I used a no-brand product until now, but I changed it to this one because it seems to be handled. There was never leakage of air either for no-brand products nor for any of our products.