Max M

Is the size listed the 'American' size or the 'European' size? In other words, which size corresponds to a '48'?

I just bought the black diamond heavyweight screen tap gloves in a size small. I'm thinking of getting these overgloves to put over them. Do you think I should get a size small or a size medium? I obviously don't want them to be slim like the screen tap gloves, but I wasn't sure if they run big or 'true to size' since they are overgloves Thanks