The ProMag SMI29 is a 6-round magazine purpose-built for the Smith & Wesson M&P Shield in .40 S&W, designed to give you a reliable spare or backup magazine for your carry gun. Whether you run a Shield for concealed carry, home defense, or off-duty use, having an extra magazine on hand means more practice ammo downrange and peace of mind knowing you've got reload capacity ready to go. ProMag backs their design with a lifetime warranty and manufactures these magazines in Phoenix, Arizona.

Built from heat-treated blued-steel components paired with ProMag's proprietary TECHNAPOLYMER construction and an anti-fatigue spring, the SMI29 is engineered to handle extended loaded storage. ProMag's design philosophy lets you load this magazine and keep it ready for up to six years without the spring losing its snap—critical for a magazine that might live in a range bag, nightstand, or backup holster for months between range sessions.

At 6 rounds, the SMI29 matches the M&P Shield's single-stack, subcompact footprint, meaning it won't print under your shirt or add bulk to your kit. It's a straightforward, no-frills magazine: good steel, proven spring technology, and the kind of reliability you need from a defensive firearm accessory.

The ProMag SMI29 is a 6-round magazine purpose-built for the Smith & Wesson M&P Shield in .40 S&W, designed to give you a reliable spare or backup magazine for your carry gun. Whether you run a Shield for concealed carry, home defense, or off-duty use, having an extra magazine on hand means more practice ammo downrange and peace of mind knowing you've got reload capacity ready to go. ProMag backs their design with a lifetime warranty and manufactures these magazines in Phoenix, Arizona.

Built from heat-treated blued-steel components paired with ProMag's proprietary TECHNAPOLYMER construction and an anti-fatigue spring, the SMI29 is engineered to handle extended loaded storage. ProMag's design philosophy lets you load this magazine and keep it ready for up to six years without the spring losing its snap—critical for a magazine that might live in a range bag, nightstand, or backup holster for months between range sessions.

At 6 rounds, the SMI29 matches the M&P Shield's single-stack, subcompact footprint, meaning it won't print under your shirt or add bulk to your kit. It's a straightforward, no-frills magazine: good steel, proven spring technology, and the kind of reliability you need from a defensive firearm accessory.