These steins using soft past porcelain with or without markings are all Capo di Monte style steins as the original royal factories are not known to have ever manufactured steins. Often they will feature the blue Fluer de Lis and Fluer de Lis over N markings used by the original factories but they are in fact not from those factories. The Capo di Monte style steins can be difficult to date but this appears to be a relatively modern one. The value on one like this can vary considerably. There are a couple of articles on these style steins in the Stein of the Month section on this site.