I think the idea is that you get two for the price of one. Just a guess though. The cutting lengths look a little short to me but then again I've never used a double ended file. I'll stick with the regular files. A Bahco costs around £6 and will sharpen around 20 saws (according to P.Sellers). I don't think he means major tooth shaping but still, it's very little money per saw even if one file services just 3 or 4 saws.