Bersa(R) magazine is designed for compatible Thunder High Capacity pistols chambered in .40 S&W. The detachable magazine provides a 13-round capacity and features a black finish. It is configured as a replacement or additional magazine for compatible Bersa Thunder High Capacity pistols.Key Features Designed for compatible Bersa Thunder High Capacity pistols Designed for .40 S&W ammunition 13-round capacity Detachable box magazine design Black finishBersa(R) manufactures firearms magazines components and accessories for sporting recreational and defensive applications. The company offers factory accessories designed for compatibility with its firearm platforms. Bersa products emphasize functional design durable construction and dependable operation.