.45 ACP HD/+P, Full-Size; 8 Round Capacity, Lo-Profile Steel Base Pad; Increases Reliability in ALL 1911 Pistols; Maximum strength-up to 25% stronger than standard 1911 mag springs for superior reliability with defensive and +P loads and more positive slide lockback; Maximum longevity MAX flatwire spring will never lose optimum feeding tension as long as you own the magazine -guaranteed! Extensively tested by the Wilson Combat Shooting Team and testfire crew.; Aircraft Grade Certified Stainless Steel Tube Resists Corrosion; Observation Slots Moved to the Rear of the Tube, Located Exactly Where They Need to be to Maintain the Structural Integrity; Proprietary, Custom Designed Welding Process; Proprietary Multi-Step Tumbling and Finishing Process Provides Smooth Follower Operation and Insertion into the Weapon; Maximum corrosion resistance-heat treated stainless MAX spring won't corrode in high humidity or marine environments-a leading cause of service pistol spring fatigue