ProMag AR-15 Roller Follower Magazine 5.56mm Black Polymer 30/rd F3FF0F62 ZM. Experience a smooth anti-tilt rolling feed with the revolutionary ROLLERFOLLOWER for maximum friction reduction. Magazine is built with their ANTI-FATIGUE chrome silicon springs - so you can keep them loaded and stashed for up to 6 years without worry. Specifications for ProMag AR-15 Roller Follower Magazine 5.56mm Black Polymer 30/rd F3FF0F62: Manufacturer: ProMag Color: Black Fabric/Material: Polymer Magazine Capacity: 30 Round Caliber: 5.56x45mm NATO Gun Type: Rifle Quantity: 1 Included Accessories: Standard Features of ProMag AR-15 Roller Follower Magazine 5.56mm Black Polymer 30/rd: Rollermag Reinvents Smooth Anti-Tilt Rolling Feed Revolutionary Rollerfollower Maximum Friction Reduction Anti-Fatigue Chrome Silicon Springs Package Contents: ProMag AR-15 Roller Follower Magazine 5.56mm Black Polymer 30/rd ProMag's new Rollermag reinvents the wheel by adding them to an anti-tilt follower in a Technapolymer magazine body. Experience a smooth anti-tilt rolling feed with the revolutionary ROLLERFOLLOWER for maximum friction reduction. Magazine is built with their ANTI-FATIGUE chrome silicon springs - so you can keep them loaded and stashed for up to 6 years without worry. ZMRM30