SSD for MacBook Air model A140?

They are available but I am not finding an MBA from 2011 whose "A" number is A140. Those are four digit numbers—A1370 and A1369 for the two 2011 models—so please verify so we give you accurate and appropriate information. Our track record with guessing is rather abysmal!

The A number can be too ambiguous for accurate model ID. Easier to do "About this Mac..." form your Apple menu and tell us the SUB-MODEL that shows, including screen size:

Once we pin down the exact model, I can provide a link to the firm from which I buy my SSDs.

OWC has some nice ones and will sell you the exact one for your macbook air. This year i purchased a Fleding feather ssd drive 265 gb from amazon that can run Mojave from Amazon. The manufactures still make them for all macbook airs that can have their ssd exchanged.

I hope this helped.