The maglula loader/unloader is simple to use in either loading or unloading mode. The loader/unloader eliminates thumb pain wear on feed lips and prolongs magazine life. It is crafted from durable reinforced polymer is lightweight and is reliable in all weather. This model is compatible with 5 10 15 20 and 25-round AR10B gen ii type metal 7.62/.308 win magazines.Caliber: 308 Win/7.62x51Finish: BlackMaterial: PlasticType: Loader/UnloaderModel Fit: AR-10B Gen II