I purchased a set of two Pearce grip extensions for my S&W Shield with the intension of putting one on the 7 round magazine and giving the other one to a friend for his Shield. Then it crossed my mind to see if the other one would fit my 8 round magazine. To my delight, it did. In fact, the grip extension on the 8 round magazine makes for the perfect grip length. I will probably purchase another 8 round magazine and spacer and install a grip extension on it.