Apex Tactical Specialties Glock Ultimate Safety Plunger. 40 S&W .357 Sig caliber pistols and will smooth out the trigger take-up when compared to the original factory component. The Ultimate Safety Plunger maintains proper safety function even when timing has been adjusted through the installation of aftermarket trigger systems. Expected Results: Smooths out the trigger take-up. Maintains proper safety function. Not for use in Gen 5 models. Specifications for Apex Tactical Specialties Glock Ultimate Safety Plunger: Manufacturer: Apex Tactical Specialties Gun Make: Glock Condition: New Caliber: .357 SIG 9mm Luger .40 S&W 10mm Auto Package Contents: Apex Tactical Specialties Glock Ultimate Safety Plunger Apex Tactical Specialties 102-102: Glock Ultimate Safety Plunger