
Availability: In Stock
Current Stock: Out of stock
The Geissele Automatics Mk18 16" Super Modular Rail brings competitive-grade modularity and Arca-Swiss quick-release capability to your AR15 build. Built on the proven MK16 platform, this handguard combines a slim, low-profile design with Geissele's reputation for precision manufacturing—ideal for shooters who demand versatility without bulk. The flat bottom integrates seamlessly with Arca-Swiss mounting systems, letting you slide accessories into any position along the rail for rapid configuration changes at the range or in the field.
Machined from 7000 Series aluminum, the MK18 delivers the rigidity and accuracy you need in a free-float platform without unnecessary weight. Its proprietary 2.25" barrel nut ensures the rail stays true along its entire length, critical for precision work. M-LOK attachment points run across the left, right, bottom, and upper 45-degree sections, giving you unmatched modularity for lights, grips, switches, and other tactical or competition gear. Every MK18 ships mil-spec AR15 compatible and is finished in durable Type 3 Hardcoat Anodize for long-term durability in hard use.
At 17 ounces (18.4 oz with barrel nut), this 16" rail won't tip your balance forward. Whether you're building a precision rifle, a competition shooter, or a general-purpose tactical AR, the MK18 gives you the platform to adapt and evolve your setup without swapping the whole handguard.
| Length | 16" |
| Material | 7000 Series Aluminum |
| Finish | Type 3 Hardcoat Anodize |
| Color | Black |
| Height | 2.08" |
| Inner Diameter | 1.26" |
| Outer Diameter | 1.59" |
| Weight (rail only) | 17 oz |
| Weight (with barrel nut) | 18.4 oz |
| Attachment Type | M-LOK, Arca-Swiss |
| Compatibility | Mil-spec AR15 pattern rifles |
Yes, the Mk18 is fully compatible with mil-spec AR15 pattern rifles and will fit standard AR15 receivers.
Yes, the 35mm Arca-Swiss flat base with 45-degree dovetail allows you to slide compatible mounts and accessories into any position along the rail without tools.
The handguard features M-LOK attachment points on the left, right, bottom, and upper 45-degree sections. It also integrates Arca-Swiss compatibility on the flat bottom for quick-release accessories.
The Mk18 ships with the rail and Geissele's proprietary 2.25" barrel nut. Always verify specific contents with your retailer at point of purchase.

SKU: 167526920 • Weight: 1.36oz





Availability: In Stock
Current Stock: Out of stock
The Geissele Automatics Mk18 16" Super Modular Rail brings competitive-grade modularity and Arca-Swiss quick-release capability to your AR15 build. Built on the proven MK16 platform, this handguard combines a slim, low-profile design with Geissele's reputation for precision manufacturing—ideal for shooters who demand versatility without bulk. The flat bottom integrates seamlessly with Arca-Swiss mounting systems, letting you slide accessories into any position along the rail for rapid configuration changes at the range or in the field.
Machined from 7000 Series aluminum, the MK18 delivers the rigidity and accuracy you need in a free-float platform without unnecessary weight. Its proprietary 2.25" barrel nut ensures the rail stays true along its entire length, critical for precision work. M-LOK attachment points run across the left, right, bottom, and upper 45-degree sections, giving you unmatched modularity for lights, grips, switches, and other tactical or competition gear. Every MK18 ships mil-spec AR15 compatible and is finished in durable Type 3 Hardcoat Anodize for long-term durability in hard use.
At 17 ounces (18.4 oz with barrel nut), this 16" rail won't tip your balance forward. Whether you're building a precision rifle, a competition shooter, or a general-purpose tactical AR, the MK18 gives you the platform to adapt and evolve your setup without swapping the whole handguard.
| Length | 16" |
| Material | 7000 Series Aluminum |
| Finish | Type 3 Hardcoat Anodize |
| Color | Black |
| Height | 2.08" |
| Inner Diameter | 1.26" |
| Outer Diameter | 1.59" |
| Weight (rail only) | 17 oz |
| Weight (with barrel nut) | 18.4 oz |
| Attachment Type | M-LOK, Arca-Swiss |
| Compatibility | Mil-spec AR15 pattern rifles |
Yes, the Mk18 is fully compatible with mil-spec AR15 pattern rifles and will fit standard AR15 receivers.
Yes, the 35mm Arca-Swiss flat base with 45-degree dovetail allows you to slide compatible mounts and accessories into any position along the rail without tools.
The handguard features M-LOK attachment points on the left, right, bottom, and upper 45-degree sections. It also integrates Arca-Swiss compatibility on the flat bottom for quick-release accessories.
The Mk18 ships with the rail and Geissele's proprietary 2.25" barrel nut. Always verify specific contents with your retailer at point of purchase.
SKU: 167526920 • Weight: 1.36oz
