Earlier counterfeits of Montblanc rollerball refills were easy to recognise because original refills did not fit the counterfeit writing instruments. Current counterfeits of the rollerball refills barely differ from the original. The only reliable distinguishing feature is a number on the back of the refill, present on the original and missing on the counterfeit. When turning the rollerball refill, hardly any differences can be seen; the Pix logo may appear somewhat larger on the fake, which, however, is only noticeable in direct comparison. Current counterfeits fit without problems into original Montblanc writing instruments and, conversely, original refills also fit current counterfeit rollerballs.