Opening and closing mechanism
Fun fact: if you ride a motorbike on cobblestone streets of Rome everyday to and from work, the mechanical pins that hold on the front cover of the Pack may rattle out over time.
Luckily this seems to be a very rare occurrence. Still, most of the pins in the pack are secured on both ends from the possibility from rattling out over time, but these two in particular got overlooked.
Future packs will have stopper on both ends of the pins to prevent the issue. In the interim, a small dab of glue can be added to secure the pins.
In some Packs, the mechanical arms can rub on the sides when opening and closing. The result is a bit of added friction and a subtle but audible sound.
We're not yet certain which part(s) irregularities are causing this, as there are so many interfacing areas. We are currently investigating the root cause and potential prevention measures.