I’m pretty sure these are meant to be on the Mastrena 2s, visible from the lobby & corresponding with the hoppers I guess

I had the same issue when my liscensed store got the mastrena 2. Our dm said there should be stickers to order instead of the metal signs but those were all we could find. I just used some double sided stick stips. Sort of like a command strip, it was the only thing that got them to stick to the hoppers

Also there's a plastic film over them you'll wanna take off so they look better. Took us two weeks till we noticed

once you take the plastic off they should stick to the black strip on the bottoms of the hoppers on the customer facing side. google mastrena 2 and there are pictures of it. :)

They go on the bean hoppers! So people know what kind of espresso we have