Hey @OBojahr HubSpot products is really designed mainly for the quotes/invoicing tool and not as a stock management solution. You can create custom properties for products however, you could create a “stock level” product to store the stock levels in here if you wish. These would not be automatically updated by HubSpot however, you could either need to manually update them, set up automation (in a workflow) to update them or update them via an integrated system.
There are a few options within the HubSpot ecosystem for integrations which can manage stock levels, I know shopify is a large, HubSpot built integration off the top of my head. If this is something you’re interested in, it might be worth having a look on the HubSpot app ecosystem to see if there are solutions created already. If you have a stock management solution already I’d definitely recomend looking into integrating your already establish system into HubSpot to manage this!