It's an acetate, and just about every acetate plays with background noise/hiss. I think the seller is being very honest in their description, and good on them for being so clear, although the reserve they have on it could be another matter
For me, acetates are wonderful pieces of history. I know that many couldn't care less about them, but how many copies of an acetate exist in comparison to the number of 45s of that track that get pressed - and how many of these fragile acetates survive the rigours of age?
In a scene that values a 45 with a certain colour label higher than those without it, or thinks that the difference in lettering or design used on a release can increase or decrease the value of a 45, then why more don't value acetates for the extreme rarities that they are is beyond me. Still, the longer people continue to dismiss them, the happier I become - regardless of their sound quality...