I have tested the pen on my Kindle Paperwhite. I had not fixed than usual pressing, but I still felt it was a very accurate. If I for example, wanted to highlight a piece of text in an e-book, the mark was sometimes marked one line too far up, even though I had definitely clicked the bottom line. Here, then, must be taken very carefully, which is not always easy due to the sinking of the small softballs to the pen tip, as this the input surface of course increases again.