A small tool to open counters!
the key can open counters with 6mm square key.
At the following address you can find the other key sizes:
Universal key:https://makerworld.com/en/models/456859#profileId-364804
7mm square key: https://makerworld.com/en/models/456892#profileId-364826
8mm square key: https://makerworld.com/en/models/456897#profileId-364841
9mm square key: https://makerworld.com/en/models/456904#profileId-364851
Happy printing!