Universal Pistol Mag CarrierEach Northern Pine Concealed universal mag carrier is formed using a specifically designed CNC mold. Using our Magazine Retention Device, it allows the shooter to make incremental adjustments to the retention of their mag draw. Our universal magazine carriers fit the following magazines: Single Stack: Single Stack 9mm Magazines Single Stack . 40 Magazines Single Stack . 45 ACP Magazines Double Stack: Double Stack 9mm Magazines Double Stack . 40