Description What makes our Mags unique… All of our mags are engineered through CAD (Computer Aided Design) systems and manufactured to SAE standards in an ISO 9001:2000 approved manufacturing facility right here in the USA. Our injection molds are cut from P20 pre-hardened tooling steel and our retractable cores are cut from S-7 heat treated steel. This gives us absolute accuracy of all mag components for years to come. Longevity Gives Us Perpetual Performance. The Dupont™ composite/glass-filled polymer was specifically chosen to provide us with an extremely durable, internally slick, fast feeding mag that will provide years of service. Our springs are slightly longer to provide a more uniform pressure and are specially coated to provide smoother action along with resisting moisture. All of our mag designs are tested for perfect fit, smooth, fast, reliable feeding and durability. Continuous smooth feeding is mandatory; therefore, we tested our mags with a variety of ammo from various manufacturers. Knowledge Gained Was Knowledge Used. Our Mags Feed Flawlessly! Ammunition used for testing included: American Eagle – Bernaul – Brown Bear – Federal – Fiocchi – Golden Tiger – Hornady – New Lake City – Remington – Seller & Bellot – Speer – Ultramax – UMC – V Max – Winchester– Wolf. (All of the fore mentioned companies are either registered or trademarked.) Each mag is sealed in a 4 mil plastic sleeve with mag warranty information enclosed. Our Tech Support and/or five year free replacement policy is one of the best. This is a once-sold-forget-it item for the dealer. We handle everything after the sale on the rare occasion that there should be a manufacturing defect.