Made of 420 Stainless Steel that gives a great resistant to corrosion; very long lasting due to the greater strength given by the heat treatment. Polish inside for an easy and smooth tube loading; feeding and performance that exceed all expectations. Fits 2011 Pistols The spring/follower and polymer base pad was designed to maximize capacity and reliability. Capacity: c/38/9 – 27+1rds. This magazine doesn’t stop the Slide back when empty.