These Service Packs contain all the springs needed to bring older guns that may have weak or broken springs back to original working condition. A perfect upgrade that will improve function and reliability. Contains Wolff recoil spring, striker spring, trigger spring, extractor plunger spring and firing pin block spring. DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.