Hello Gerhard. I don't have an Air, but if it says "Suitable model Macbook Air 13'', MacBook Pro 13", then it will certainly fit very well. The height of the Air of only 1.13 cm (compared to the Macbook Pro of 1.56 cm) is really not that much - unless you don't mind the 0.43 cm difference.

In any case, the product is great, I've had it for years and always have it with me when a bag is too much (sometimes I even take it with me in my bag).