Staying true to Check-Mates standard of excellence, the 1911 .45 caliber magazines are produced using the finest American milled stainless and high carbon steel. The proven inherent reliability of these magazines practically speaks for itself. Check-Mate guarantees outstanding quality and maximum longevity for the .45 caliber magazine by through hardening each tube and utilizing proprietary welding techniques. In addition, many of our magazines house Check-Mates patented follower, designed with an extended front skirt with an anti-friction self-lubricating finish and proper dimple placement for exceptional feed and function with every round.