I actually disagree to some of the negative comments:
Yes, the thread could be a bit more
invisible, but his is always a lighting issue.
Yes, sanding the hole a bit increases the quality
eliminating sharp edges - just do it and it becomes a quality product!
The Pro: It is just
a standard pen in your pocket: An inconspicuous device. Of course you can't have it examined. But,
why should you? Why should it write?
Would you ever consider to have another reel being
examined? The advantage is that you can always have it in full view. Nothing suspicious.The strength
of the thread is rather satisfactory.
Finally, the battery is never dead ;-)
The
instruction video though is not a masterpiece.