80Packs Rare Earth Magnets, 5 Different Size Small Round Magnets for Crafts, Neodymium Magnets, Round Magnets, Small Magnets, Mini Magnets(Sliver)

Are these n52? "i think so" does not cut it. for a professional seller, you need to know dont want to waste my time if they arent.

Will this hold something on an enclosed trailer driving on interstate? Like a tag or flag on the trailer?

are these really stainless steel? it looks like nickel to me, and all other sellers claim "nickel-scratch proof". Havent seen other stainless offers.

would they work on a cruise ship cabin room door