FEATURES:

ProMag replacement magazines are known for their durability, reliable performance, and compatibility with a wide range of firearms. Expertly machined for exceptional quality and guaranteed to feed and function for every shot. ProMag magazines include a lifetime guarantee, if you ever have a problem with their magazines; simply return them to ProMag for replacement.
 

Brand: ProMag
Category: Magazines
Model: Standard
Fits: Sig Sauer P229
Caliber: .40 S&W / .357 SIG
Capacity: 12 Rounds 
Body Material: Steel 
Spring Material: Heat Treated Chrome-silicon Wire 
Follower Material: DuPont Zytel Based Polymer 
Follower Color: Black 
DuPont Zytel Based Polymer Baseplate
Finish: Blued