Spacer is to provide better funtioning of 9mm ammo in the STI 38 super magazines. Flap on side is to be used with +2 or 3 Base pads such as the Dawson or Grams. The flap will not work with slide on base pads. For 170mm magazines and 140mm with flush or +1 pads remove flap and cut to length if needed. Must be used with a 9mm follower. Pictured with the spacer is the new Arredondo Teflon 9mm follower. Buy as a kit or seperate.
Followers only work with Arredondo Springs