If the cap sinks about 2 mm too little onto the body, with high probability a fountain-pen cap (typically from the 144 Meisterstück) is fitted whose inner cap is too large for the rollerball. The inner cap of a rollerball is significantly smaller and only encloses the ball tip of the refill. Exchanging only the inner part is not possible, since Montblanc principally does not sell spare parts to end customers — this also serves to curb the counterfeit industry. An original rollerball inner cap as a repair item costs in experience at least 50 euros via the works service.