Constructed of durable, corrosion-resistant stainless steel with a welded base plate, the Check-Mate® 1911 9mm 9-Round Stainless Steel Magazine offers unmatched reliability in virtually any environment. The high-tensile steel spring and stainless steel follower deliver exceptionally smooth operation, while the factory-machined witness windows allow for quick, visual round counts while on the move. Better yet, this magazine is compatible with virtually any 1911 handgun, chambered in 9mm for versatile field performance.