S&W M&P Magazine Springs Extra Power +10% (XP) by Wolff

Magazine spring are available for M&P 9mm and .40/.357 magazines and are +10% extra power over factory springs.  Springs are for use in the following magazines:

   9mm - 17 Rounds                                            .40/.357 - 15 Rounds
   9mm - 12 Rounds (Compact)                            .40/.357 - 10 Rounds
   9mm - 10 Rounds                                            .40/.357 - 10 Rounds (Compact)
   9mm - 10 Rounds (Compact)