Only gas cartridges are possible with this model. No gas cylinders.

The cartridges fit nicely in the back and last about 24 hours. You can probably find an adapter to connect it up to a larger cylinder.

Cartridge only

You can only use gas cartridges for this cool box.

The ACX 3 40G can only be operated with cartridges, ACX3 40 is for 30mbar gas connection (with gas cylinders and pressure reducer).
It would be nice if this were described in detail in the specifications.
Greetings