A khiyar (option) that comes into effect if a person buys an item in barter for unseen items in a container. The seller of that object doesn’t know the quantity or type of the objects placed in the container. In this case, the seller has the option after opening the container or box and checking its contents to choose between concluding and cancelling the sale. The name “khiyar al-kimmiyya” was given by the Hanafis. It differs from khiyar al-ru’yah in that the latter doesn’t apply when the unseen item is money.

Khiyar al-kimmiyya is an Arabic term (خيار الكمية) that translates as quantity option.