Will the iPad Air 4 cover fit the iPad Air 5?

Yes. They are identical in size and shape.

I just want to know which magnetic cover will fit my old relable A1475 iPad...I have worn out so many of them....I foget which generation it is...I just know by the number on the back.

That is an iPad Air 1 (first generation). I'm sure you can find something you may like on Amazon for that model device.

which number is th A1475 ....Ipad Air 4 or 5?

Model number A1475 is a first generation iPad Air, from 2013. A long time ago.

So again I ask...what size cover fits the Ipad Air A1475? I thought one of the newer Ipads was actually the same size as the A1475 and that cover would also fit.

Nothing Apple sells currently will fit an iPad released almost 10 year ago.

Go to www.amazon.com and type this in the search bar there -- "ipad air 1 cases"

You can do your own searching.