If they fit the Andis super 2 speed then yes they will fit your Oster A5. I have both these clippers and the blades are the same. I actually prefer the andis blades over the oster even on my oster clipper.
They will fit, but will they last for the long haul? I have gotten my andis and oster blades sharpened over and over and they are still doing good after some have been sharpened more than 10 times. Will the discount ones last as long? I would be cautious about a brand I do not know.