What is the S15 +2 Magazine Extension?
The Shield Arms S15 +2 Magazine Extension is a precision-machined aluminum baseplate extension that adds 2 additional rounds to your S15 Magazine, increasing total capacity from 15 to 17 rounds. When combined with the S15 magazine platform, this gives your Glock 43X or 48 a total capacity of 17+1 rounds—nearly doubling the factory 10-round capacity.
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Maximum Capacity Without Compromise
The S15 +2 Magazine Extension represents the perfect balance between increased capacity and concealability for Glock 43X and 48 owners. While factory Glock magazines limit you to just 10 rounds, this extension—when paired with the Shield Arms S15 Magazine—delivers a remarkable 17+1 round capacity in a package that remains discrete enough for everyday concealed carry. The extension adds minimal length to your pistol while nearly doubling your available ammunition, giving you the confidence of full-size capacity in a micro-compact platform.
Machined from aerospace-grade 6061 billet aluminum and finished with durable Type-2 anodizing, the S15 +2 Extension is built to withstand the demands of daily carry, competitive shooting, and training. The thoughtful engineering includes index cuts for positive grip during magazine changes, a unique floor plate design that allows magazine maintenance without extension removal, and compatibility with both Shield Arms magwells and most aftermarket flared magazine wells. Each extension includes an upgraded 11-coil power spring designed specifically for reliable feeding with the increased capacity.
Whether you're a concealed carry permit holder seeking maximum defensive capability, a competitive shooter looking for an edge, or a firearms enthusiast who demands the best performance from your Glock 43X or 48, the S15 +2 Magazine Extension delivers professional-grade capacity enhancement backed by Shield Arms' reputation for precision manufacturing and innovation.
Key Features
- +2 Round Capacity: Increases S15 magazine capacity from 15 to 17 rounds for a total of 17+1 in your Glock 43X/48
- Premium Construction: CNC-machined from billet 6061 aluminum for exceptional strength-to-weight ratio
- Type-2 Anodized Finish: Available in multiple color options including black, FDE, grey, OD green, and mud for personalization and corrosion resistance
- Innovative Floor Plate Design: Unique design allows full magazine servicing and cleaning without removing the extension
- Enhanced Grip Features: Precision index cuts machined into extension body provide positive purchase when drawing from magazine pouches
- 11-Coil Power Spring: Included upgraded spring ensures reliable feeding and optimal performance with increased capacity
- Magwell Compatible: Works seamlessly with Shield Arms Carry Magwell and most aftermarket flared magazine wells
- Made in USA: Proudly designed, engineered, and manufactured in the United States
Important: Required Components
The S15 +2 Magazine Extension is designed exclusively for use with Shield Arms S15 Magazines. It will not function with factory Glock magazines. For optimal performance and reliability, Shield Arms recommends using either the Premium S-Series Steel Mag Catch or Standard S-Series Mag Catch with your S15 magazine system.
Color Note: In 2025, the anodized shade of the 'Mud' color option was updated. Items previously purchased in Mud may not match the current shade exactly.
Technical Specifications
| Specification |
Details |
| Compatible Firearms |
Glock 43X, Glock 48 |
| Compatible Magazines |
Shield Arms S15 Magazine |
| Capacity Increase |
+2 rounds (15 to 17 total magazine capacity) |
| Material |
6061 Billet Aluminum |
| Finish |
Type-2 Anodized |
| Color Options |
Black, FDE, Grey, OD Green, Mud |
| Included Components |
Extension body, 11-coil power spring |
| Magwell Compatibility |
Shield Arms Carry Magwell, Shield Arms Premium Magwell, most aftermarket flared magwells |
| Manufacturing |
Made in USA |
| Warranty |
Lifetime warranty against manufacturing defects |
Capacity Comparison
| Magazine Configuration |
Magazine Capacity |
Total Capacity (w/ +1) |
Increase vs. Factory |
| Factory Glock 43X/48 Magazine |
10 rounds |
10+1 |
Baseline |
| Shield Arms S15 Magazine |
15 rounds |
15+1 |
+5 rounds |
| S15 Magazine + S15 +2 Extension |
17 rounds |
17+1 |
+7 rounds (70% increase) |
| S15 Magazine + S15 +5 Extension |
20 rounds |
20+1 |
+10 rounds |
Frequently Asked Questions
Will the S15 +2 Extension work with factory Glock magazines?
No, the S15 +2 Magazine Extension is engineered specifically for Shield Arms S15 Magazines and will not fit or function with factory Glock magazines. The S15 magazine uses a unique double-stack design and dimensions that differ from OEM Glock magazines.
How much length does the +2 extension add to my pistol?
The S15 +2 Extension adds approximately 0.5 inches to the overall length of your magazine and pistol. This minimal increase maintains excellent concealability while providing 2 additional rounds of capacity—offering an ideal balance for everyday carry.
Is the S15 +2 Extension compatible with magazine wells?
Yes, the S15 +2 Extension is fully compatible with the Shield Arms Carry Magwell, Shield Arms Premium Magwell, and most aftermarket flared magazine wells designed for the Glock 43X/48 platform. Always verify fitment with your specific magwell manufacturer.
Do I need to purchase a magazine catch to use the S15 magazine system?
Shield Arms strongly recommends replacing the factory polymer magazine catch with either the Premium S-Series Steel Mag Catch or Standard S-Series Mag Catch for optimal performance and reliability with S15 magazines. The steel mag catch is specifically designed to work with the S15's metal body.
Can I service or clean my magazine without removing the extension?
Yes, one of the innovative features of the S15 +2 Extension is its unique floor plate design that allows you to fully service and clean your S15 magazine without removing the extension. This design saves time during maintenance and ensures you can keep your magazines in top operating condition.
What is the Spring for Life guarantee?
Shield Arms' Spring for Life guarantee ensures that if your magazine spring wears out at any point during the life of your S15 magazine or extension, Shield Arms will replace it for free. This lifetime spring replacement guarantee demonstrates our commitment to long-term reliability and customer satisfaction.
How does the +2 extension compare to the +5 extension?
The S15 +5 Extension adds 5 rounds (total of 20 in the magazine) versus the +2's 2 additional rounds (17 total). The +2 extension offers superior concealability with minimal length increase, making it ideal for everyday concealed carry. The +5 extension provides maximum capacity and is popular for home defense, competition, and range use where concealability is less critical.
Is the S15 +2 Extension legal in all states?
Magazine capacity laws vary by state and jurisdiction. Some states have restrictions on magazine capacity that may limit the use of extended capacity magazines. It is the buyer's responsibility to know and comply with all federal, state, and local laws regarding magazine capacity. Shield Arms does not provide legal advice—consult with a qualified attorney or local law enforcement if you have questions about legality in your area.
What colors are available for the S15 +2 Extension?
The S15 +2 Extension is available in multiple Type-2 anodized color options including Black, Flat Dark Earth (FDE), Grey, OD Green, and Mud. This allows you to match or complement your firearm's finish. Note that in 2025, the Mud color shade was updated, and older Mud-colored items may not match newer production exactly.
Does the extension affect reliability or feeding?
No, the S15 +2 Extension is designed to maintain the exceptional reliability of the S15 magazine system. Each extension includes a precision-engineered 11-coil power spring specifically designed for the increased capacity. When properly installed and maintained, the S15 +2 Extension provides reliable feeding and function equal to or better than factory configurations.
Can I purchase magazines with the extension already installed?
Yes, Shield Arms offers S15 magazines with extensions pre-installed for added convenience. This ensures proper installation from the factory and allows you to start using your extended-capacity magazines immediately upon delivery.
What warranty comes with the S15 +2 Extension?
Like all Shield Arms products, the S15 +2 Magazine Extension is backed by a 100% lifetime warranty against manufacturing defects. Additionally, the included spring is covered under Shield Arms' Spring for Life guarantee, which provides free spring replacement for the life of the product. This comprehensive warranty coverage reflects our confidence in American manufacturing quality and our commitment to customer satisfaction.
Who Should Buy the S15 +2 Magazine Extension?
- Concealed Carry Permit Holders: Everyday carriers who want maximum defensive capacity without sacrificing concealability in their Glock 43X or 48
- Law Enforcement Officers: Off-duty or plainclothes officers seeking enhanced capacity in a compact, discrete platform
- Competitive Shooters: USPSA Carry Optics and other competitive disciplines where the Glock 43X/48 platform is used and capacity matters
- Home Defense Enthusiasts: Those who rely on their Glock 43X/48 for home protection and want additional rounds available
- Firearms Trainers: Instructors and students who want to maximize training efficiency with fewer magazine changes during range sessions
- Glock 43X/48 Owners: Anyone who already owns and carries a Glock 43X or 48 and wants to upgrade capacity cost-effectively
- Existing S15 Magazine Users: Current S15 magazine owners looking to add modest capacity without the length of the +5 extension
Installation & Setup
Installing the S15 +2 Magazine Extension is straightforward and can be completed in minutes with basic tools. The extension comes with detailed instructions, and the process involves disassembling your S15 magazine, replacing the factory baseplate and spring with the extension components, and reassembling. For visual installation guidance, detailed videos, and step-by-step instructions, visit our Installation Guides page. If you prefer to start with a ready-to-use solution, consider purchasing S15 magazines with the +2 extension already installed from the factory.
Related Products & Accessories
- Shield Arms S15 Magazine - Required for use with this extension. The foundation of the high-capacity system, featuring a revolutionary double-stack metal design that holds 15 rounds in the same footprint as a factory 10-round magazine.
- Premium S-Series Steel Mag Catch - Highly recommended for optimal S15 magazine performance. Machined from steel to provide superior durability and proper engagement with S15 magazines compared to factory polymer mag catches.
- Standard S-Series Mag Catch - An affordable steel mag catch option that provides reliable function with S15 magazines at a lower price point than the Premium version.
- S15 +5 Magazine Extension - For maximum capacity when concealability is less critical. Adds 5 rounds for a total magazine capacity of 20 rounds, ideal for competition, range use, or home defense applications.
- Shield Arms Carry Magwell - Enhances reload speed and magazine insertion while maintaining a compact profile. Fully compatible with the S15 +2 Extension for faster, more consistent magazine changes during defensive scenarios or competition.
American Quality, Lifetime Confidence
Every Shield Arms S15 +2 Magazine Extension is proudly designed, engineered, and manufactured in the United States using state-of-the-art CNC machining and quality-controlled processes. We stand behind our products with a 100% lifetime warranty against manufacturing defects and our exclusive Spring for Life guarantee. When you choose Shield Arms, you're choosing American innovation, precision manufacturing, and a company committed to supporting the shooting community with products that perform when it matters most.
