There's not a whole lot that's special about this cartridge. It's Super Mario Bros., but it isn't the legitimate Nintendo Co., Ltd. release.
What might be a bit interesting about this pirate is the information on the label. Many pirate labels never even try to emulate a legitimate label. But this one is somewhat convincing, aside from Family Computer having been written in English. I'm fascinated by the product code, because it makes me curious what "LB" stands for; maybe the makers. And the code is numbered "35," which might mean there are at least 34 other pirated games made by the same company.
This pirate came as a part of a lot from eBay and wouldn't be worth but a couple of dollars.