The product revision number is printed on the giftbox bottom.
If no revision number on your box, use Rev 1
A selection of motherboards interferes with the cooler. Below is a list of motherboards which have been confirmed to have this problem.
Below list is non exhaustive, some further models of motherboards may also present incompatibility. ARCTIC is providing the below information as-is and to the best of its knowledge. Below information will be updated as per discovery of such incompatibility.