ProMag Magazine 1911 Government, Commander 45 ACP 40-Round  Black Polymer Drum 

These ProMag magazine bodies and followers are injection molded from strong, lightweight polymer. The springs are precision wound using heat-treated chrome silicon wire. The result is quality, consistency, durability and reliability.
 

ACT-MAG is becoming well known throughout the firearms industry as one of the finest magazine manufacturers in the world. ACT-MAG magazines are engineered to function flawlessly under the toughest shooting conditions. Initial offered to the shooting community for 1911 Government Model magazines in 8rnd. Capacity