If you check the store for NN 5 you will notice that it is mentioned : " Purchasers of this package may trade-up to NN5 with upper arm 15 degree stops in mid 2008 (est. Aug) for a nominal fee. "

Is this a new arm ? is it better than the current NN5 upper arm ? ....... Sorry But I didn't understand what you mean. Would some one please explain . Probably show us some picture.