
Availability: In Stock
The Magpul MAG591-BLK M-LOK 7-Slot Polymer Rail is a lightweight accessory mounting solution for builders and shooters who want to add lights, grips, or other Picatinny-spec equipment to their AR platform without the weight penalty of aluminum. At 3.3 inches long with seven M-LOK slots, this polymer rail bridges the gap between your handguard and your tactical setup—giving you real estate for vertical grips, tactical lights, or other common rail-mounted gear wherever your M-LOK handguard has available slots.
Built from Magpul's proprietary reinforced composite, the rail delivers strength and durability in a package that won't bog down your rifle. The design includes recoil and impact mitigation lugs to absorb stress from mounted accessories, and beveled edges eliminate the sharp corners that snag gloves and gear in the field. Since it mounts directly to M-LOK T-nuts, installation is straightforward—no special tools or gunsmithing required. All mounting hardware is included.
Whether you're setting up a dedicated hunting rifle, a competition gun, or a tactical build, the MAG591-BLK gives you the flexibility to position accessories exactly where you need them. Made in the U.S.A., it's the kind of modular solution that defines the AR platform's appeal: upgrade it your way, step by step.
| Product Name | Magpul M-LOK 7-Slot Polymer Rail |
| Model Number | MAG591-BLK |
| Overall Length | 3.3 inches |
| Slot Count | 7 M-LOK slots |
| Material | Reinforced composite polymer |
| Color | Black |
| Mounting Standard | M-LOK T-nut compatible |
| Hardware Included | Yes |
| Manufacturer | Magpul Industries |
Yes—the MAG591-BLK is designed for any M-LOK compatible handguard or forend, whether aluminum or polymer. It mounts directly to M-LOK T-nuts using the included hardware.
The rail accepts standard 1913 Picatinny-spec rail-mounted accessories, including tactical lights, vertical grips, and other common AR add-ons. With seven slots, you have multiple mounting positions to dial in your setup.
All hardware necessary to attach the rail directly to M-LOK slots is included. No additional fasteners are required.
The MAG591-BLK is made from lightweight reinforced polymer, so it adds minimal weight compared to aluminum alternatives while still delivering durability and impact mitigation through integrated recoil lugs.



SKU: 115776226 • Width: 4.2in • Height: 0.1in • Depth: 7.5in • Weight: 0.06oz





Availability: In Stock
The Magpul MAG591-BLK M-LOK 7-Slot Polymer Rail is a lightweight accessory mounting solution for builders and shooters who want to add lights, grips, or other Picatinny-spec equipment to their AR platform without the weight penalty of aluminum. At 3.3 inches long with seven M-LOK slots, this polymer rail bridges the gap between your handguard and your tactical setup—giving you real estate for vertical grips, tactical lights, or other common rail-mounted gear wherever your M-LOK handguard has available slots.
Built from Magpul's proprietary reinforced composite, the rail delivers strength and durability in a package that won't bog down your rifle. The design includes recoil and impact mitigation lugs to absorb stress from mounted accessories, and beveled edges eliminate the sharp corners that snag gloves and gear in the field. Since it mounts directly to M-LOK T-nuts, installation is straightforward—no special tools or gunsmithing required. All mounting hardware is included.
Whether you're setting up a dedicated hunting rifle, a competition gun, or a tactical build, the MAG591-BLK gives you the flexibility to position accessories exactly where you need them. Made in the U.S.A., it's the kind of modular solution that defines the AR platform's appeal: upgrade it your way, step by step.
| Product Name | Magpul M-LOK 7-Slot Polymer Rail |
| Model Number | MAG591-BLK |
| Overall Length | 3.3 inches |
| Slot Count | 7 M-LOK slots |
| Material | Reinforced composite polymer |
| Color | Black |
| Mounting Standard | M-LOK T-nut compatible |
| Hardware Included | Yes |
| Manufacturer | Magpul Industries |
Yes—the MAG591-BLK is designed for any M-LOK compatible handguard or forend, whether aluminum or polymer. It mounts directly to M-LOK T-nuts using the included hardware.
The rail accepts standard 1913 Picatinny-spec rail-mounted accessories, including tactical lights, vertical grips, and other common AR add-ons. With seven slots, you have multiple mounting positions to dial in your setup.
All hardware necessary to attach the rail directly to M-LOK slots is included. No additional fasteners are required.
The MAG591-BLK is made from lightweight reinforced polymer, so it adds minimal weight compared to aluminum alternatives while still delivering durability and impact mitigation through integrated recoil lugs.
SKU: 115776226 • Width: 4.2in • Height: 0.1in • Depth: 7.5in • Weight: 0.06oz


