Sig Sauer P239 Recoil Spring, 9mm. This is a factory original Sig Sauer part. Made to the same high standards as the parts already found in your Sig Sauer firearm. This part will help keep your Sig Sauer Firearm in top shooting condition. From the world leader in firearms, genuine Sig Sauer parts are designed around the same relentless standards put into every pistol and rifle they make. Kit up, dress up, or replace your original parts with nothing but genuine parts from Sig Sauer.