SyncNbook connects to multiple POS systems.
POS Profile is used to connect to some of them but the others are set up through Developers Key.
Check out our Integrations page for a list of POS connections and how to set them up: Integrations
Note: If we do not have direct connection to the POS your property is using, check out Omniboost as they can connect to multiple POS systems that can then be connected to SyncNbook.