I bought this bag for my MBA 13 inches, it fits perfectly, I already had this type of cover but by dint of taking cases or black or gray bags I decided to take this one, I like many reasons, it changes. The cover in itself is worth its price, personally I was put in a shoulder bag, like that my laptop is protected from other cases found in my bag.
By cons avoid putting something heavy on it, you still have to take care, in fact it takes the form of the object when there is a pressure on it and put more or less time to regain its original shape. To avoid it abyss too quickly, put the above and still last a long time :)
