Quick Answer
What is the Shield Arms +5/4 Magazine Extension? A precision-machined aluminum magazine extension for Glock 17, 22, 34, 35, 19X, and 45 pistols that increases capacity by 5 rounds (9mm) or 4 rounds (.40 S&W/.357 SIG) while maintaining factory reliability.
The Shield Arms +5/4 Magazine Extension is engineered to maximize your Glock's ammunition capacity without sacrificing reliability or function. This premium extension is specifically designed for Glock 17, 22, 34, 35, 19X, and 45 models, adding substantial capacity for competitive shooting, law enforcement duty, and personal defense applications.
Constructed from aircraft-grade aluminum with a durable anodized finish, this extension offers the perfect balance of lightweight performance and rugged durability. The precision-machined design ensures seamless integration with factory Glock magazines while maintaining the feeding reliability Glock pistols are known for.
Capacity Increases by Caliber
- 9mm magazines: +5 rounds additional capacity
- .40 S&W magazines: +4 rounds additional capacity
- .357 SIG magazines: +4 rounds additional capacity
Key Features
- Universal compatibility with Glock 17, 22, 34, 35, 19X, 45, 47
- Aircraft-grade aluminum construction for maximum durability
- Anodized finish resists corrosion and wear
- Drop-in installation requires no permanent modifications
- Maintains factory magazine reliability and feeding
- Lightweight design preserves firearm balance
- Includes all necessary installation hardware
- Compatible with OEM and most aftermarket Glock magazines
Spring for Life Guarantee
Every Shield Arms magazine extension is backed by our exclusive "Spring for Life" guarantee. This means you'll receive free replacement springs for the life of your extension - no questions asked. Magazine springs are wear items that can lose tension over time with heavy use. Our Spring for Life program ensures your Shield Arms extension maintains peak performance throughout its entire service life. Simply contact us when you need a replacement spring, and we'll send you a new one at no charge.
Professional Applications
The Shield Arms magazine extension is trusted by professionals across multiple disciplines:
- Competitive Shooting: USPSA, IPSC, and 3-Gun competitors rely on maximum capacity for stage planning
- Law Enforcement: Officers appreciate the additional rounds for duty and backup magazines
- Training: Extended capacity reduces reload frequency during training sessions
- Home Defense: Responsible gun owners value the peace of mind from increased capacity
Installation & Compatibility
Installation is straightforward and requires no gunsmithing or permanent modifications to your firearm or magazines. Each extension includes allen wrenches and detailed instructions. The extension fits flush with standard Glock magazine base pads and maintains a clean, professional appearance.
Compatible with:
- Glock OEM factory magazines
- Most aftermarket Glock-pattern magazines
- Standard and extended base pads
Technical Specifications
| Compatible Models |
Glock 17, 22, 34, 35, 19X, 45 |
| Capacity Increase (9mm) |
+5 rounds |
| Capacity Increase (.40/.357) |
+4 rounds |
| Material |
Aircraft-grade aluminum |
| Finish |
Type III hard anodized |
| Weight |
Lightweight (maintains balance) |
| Installation |
Drop-in, no permanent modifications |
| Hardware Included |
Allen wrenches and all mounting hardware |
| Warranty |
Lifetime + Spring for Life |
| Made In |
USA |
Capacity Comparison
| Magazine Type |
Standard Capacity |
With +5/4 Extension |
Capacity Increase |
| Glock 17 (9mm) |
17 rounds |
22 rounds |
+5 rounds (29% increase) |
| Glock 22 (.40 S&W) |
15 rounds |
19 rounds |
+4 rounds (27% increase) |
| Glock 34 (9mm) |
17 rounds |
22 rounds |
+5 rounds (29% increase) |
| Glock 35 (.40 S&W) |
15 rounds |
19 rounds |
+4 rounds (27% increase) |
| Glock 19X (9mm) |
17 rounds |
22 rounds |
+5 rounds (29% increase) |
| Glock 45 (9mm) |
17 rounds |
22 rounds |
+5 rounds (29% increase) |
Frequently Asked Questions
Which Glock models is this extension compatible with?
The Shield Arms +5/4 extension is designed specifically for Glock 17, 22, 34, 35, 19X, and 45 pistols. It works with factory OEM magazines and most aftermarket Glock-pattern magazines for these models.
How many rounds does this extension add?
The extension adds 5 additional rounds for 9mm magazines and 4 additional rounds for .40 S&W and .357 SIG magazines. This brings standard Glock 17 capacity from 17 to 22 rounds, and Glock 22 capacity from 15 to 19 rounds.
Does installation require any permanent modifications?
No permanent modifications are required. The Shield Arms extension uses a drop-in design that can be easily installed and removed without altering your firearm or magazines. All necessary hardware and allen wrenches are included.
Will this extension affect magazine reliability?
No. The Shield Arms extension is precision-engineered to maintain factory Glock magazine reliability and feeding. The design has been extensively tested and is trusted by law enforcement and competitive shooters who demand consistent performance.
What material is the extension made from?
The extension is CNC-machined from aircraft-grade aluminum and features a Type III hard anodized finish for superior corrosion resistance and durability. This construction provides an optimal balance of strength and lightweight performance.
Will this work with aftermarket Glock magazines?
Yes, the Shield Arms extension is compatible with most aftermarket Glock-pattern magazines designed for models 17, 22, 34, 35, 19X, and 45. However, we recommend testing with your specific magazines to ensure proper fit and function.
Does the extension affect concealed carry?
The extension adds length to the magazine, which may extend below the grip of your pistol depending on your carry configuration. While this increases capacity, it may affect concealability. The extension is ideal for competition, duty use, range training, and home defense applications.
Is the extension legal in my state?
Magazine capacity restrictions vary by state and locality. While the Shield Arms extension increases capacity beyond 10 rounds in most configurations, legality depends on your jurisdiction. Please check your local and state laws before purchasing. Shield Arms cannot ship to restricted locations.
How much does the extension weigh?
The aluminum construction keeps the extension lightweight to maintain proper firearm balance. While adding minimal weight compared to the ammunition capacity gained, the extension preserves the handling characteristics you expect from your Glock pistol.
What's included in the package?
Each Shield Arms +5/4 extension includes the aluminum extension body, all necessary mounting hardware, and allen wrenches required for installation. Detailed installation instructions are provided to ensure proper assembly.
What is the Spring for Life guarantee?
Shield Arms provides free replacement springs for the life of your magazine extension at no charge. Magazine springs can lose tension over time with heavy use, and our Spring for Life program ensures your extension maintains peak performance forever. Learn more about Spring for Life.
Who Should Buy the Shield Arms +5/4 Extension?
- Competitive shooters in USPSA, IPSC, and 3-Gun seeking maximum capacity advantages
- Law enforcement officers carrying Glock duty pistols who need increased capacity
- Training instructors and students looking to reduce reload frequency during live-fire drills
- Home defense users prioritizing maximum ammunition availability
- Range enthusiasts who want extended shooting sessions between reloads
- Glock 17/22/34/35/19X/45 owners seeking a reliable capacity upgrade
Why Choose Shield Arms?
Shield Arms designs and manufactures premium firearm accessories with an unwavering commitment to quality and reliability. Every magazine extension undergoes rigorous testing and quality control to ensure it meets the demanding standards of professional users. Backed by our lifetime warranty and exclusive Spring for Life guarantee, and proudly Made in the USA, Shield Arms products deliver the performance and durability you can trust when it matters most.
