This is the website: hrinkow-bikes.at/bikecreator/bikes.html?categoryId=2
I'm German and can read everything but there is not a hint on what the numbers could mean. I don't think it's related to the battery or engine of an e-bike because it only says e-option as in optional and the pictures don't show e-bikes. Also the information in the dropdown menu is very limited. They don't give the full specs of the bikes.
Very weird. I would contact the seller and ask. My best guess is that it's simply a brand-specific numbering for their models. Higher number means higher specced version or something like that.