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. Kit Includes: Wolff recoil springStriker springTrigger springExtractor 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.