This magazine is a factory original made by Armalite for AR10B Rifles only. Factory parts are manufactured to the exact same specifications and tolerances and use the same manufacturing materials as the original parts which guarantees excellent fit and reliable operation.
*NOTE: This magazine is NOT compatible with traditional LR/SR DPMS style .308 Rifles. This magazine is Specific to Type "B" Armalite lowers only. Will NOT fit Type "A" lowers.