Smith & Wesson SD9 Magazine Extension


  • Industrial polymer
  • Strong & lightweight
  • Adds 4-5 rounds
  • Fits 9mm only
  • Fits USPSA 141mm gauge
  • Retention screw system
  • Uses factory spring

  • VE models need more material removed to fit

  • Watch Installation video below

  • Magazine not included
  • One (1) year warranty
  • Made in the USA


The motto at Cain Arms is keep it simple and affordable. Our magazine extensions are 3D printed out of extremely durable and heat resistant industrial polymer and are designed and tested to handle the most extreme environments you encounter. Our products have been drop tested hundreds of times and our manufacturing processes have been relentlessly refined to meet our exceedingly high standards of quality. Every part comes with a 12 month warranty against any manufacturing defect and we guarantee 100% satisfaction or your money back. If you don’t like it, return it for a full refund. Refer to the above video for any installation questions or for any problems you may encounter when using this product.

Additional information

Weight 1 oz

black, dark earth, coyote, olive drab, army green, gray, red, white, blue, orange, lime, custom color