The Wilson Combat ETM (Elite Tactical Magazine) is constructed of Aircraft Grade Certified Stainless Steel Tube and resists corrosion. The Stainless Steel ETM has one of the strongest magazine tubes ever developed, virtually eliminating feed lip cracking, tube spread and general fatigue. It has a longer body to allow for less compression on the magazine spring with no appreciable difference in size compared to seven round magazines. Utilizing an enhanced spring and the strongest body in a production magazine, failure to feed due to cracked feed lips or spring fatigue are virtually eliminated. No matter how many times you empty this magazine through your pistol, you can be assured the engineering expertise, design, material selection, manufacturing, and the quality control behind the ETM promises a lifetime of smooth and reliable operation.