The engraving under the clip reads on current models 'Made in Germany' instead of 'PIX'; that is therefore inconspicuous. The position of the serial number on the clip edge has been changed several times in the course of production and is therefore no reliable authenticity criterion. The inscription should regularly be a laser engraving; however, current counterfeits also use engravings, so this feature has lost meaning. With the large-capacity refills, variants existed over the years too. For concrete authenticity check, an enquiry to Montblanc Service via the contact form on the website with the complete serial number is recommended.