After several requests for a better trigger from the Sphinx SDP Compact pistols from customers. We finally took action and created a kit that not only makes the Sphinx SDP Compact a better combat pistol but now a contender for competition shooting. Unlike other kits on the market which have poorly made springs to retain safe operation of the firing pin during a drop incident. Our kit redesigns the the springs inside the Sphinx Sub Compact to allow for a proper reduction of hammer spring pressure felt when you pull the trigger, without compromising the safety of the pistol. We recommend you test your ammo with the shim installed and not installed to understand the hardness of your primers. With the shim installed we have had 100% success in firing all rounds we tested including the hardest we have found. With shim removed hardest primers will have issues firing. Trigger pull will be significantly reduces in both SA and DA possible with our kit, finally making it ready for fast accurate shots on target.   **Beware of other companies who are trying to knock off our kit for a little less money and sell you a product that is not made to the same standards as our the original "Sphinx Enhanced Trigger Kit" or "B&T ENHANCED TRIGGER KIT" high quality standards. Our products are made to the same Sphinx standards and made in the USA - not China, Just because they look similar and use our product name - it is not the same ...at ALL.**      **DO NOT DRY FIRE WITHOUT SNAP CAP**   WITH SHIM DA IS 8LB AND SA IS 4LB 2OZ (Measured on a stock SDP subcompact) Kit includes: Reduced firing pin spring Reduced Hammer spring  Spring seat shim   Ammo's tested and verified working: Federal American eagle ball 115gr and 147gr Tula (had issues with purple spring and some green) Winchester S&B Rem UMC Magtech Sig V Crown Hornady Crit Def and Duty   **DOES NOT WORK WITH FREEDOM MUNITIONS AMMUN