The Geissele MK4 Super Modular Rail (brand part no. 05-283S) is a 9.3-inch, Desert Dirt-finished M-LOK handguard built as Geissele’s ultra-rugged option for the AR platform. The rail is purpose-built with integrated M1913 Picatinny rail sections at the fore in the 3, 6, and 9 o’clock positions, backed by full M-LOK coverage at those same positions plus the upper 45-degree quadrants for mounting lights, grips, and other accessories. Maximum venting at the lower quadrants trims weight and dissipates heat without giving up rigidity, and the rail ships with Geissele’s proprietary 2.25-inch-long barrel nut, which increases surface contact at the receiver interface to keep the platform straight and true and improve zero repeatability during maintenance.

Key Specifications

• Measures 9.3 inches in length.
• Built as Geissele’s ultra-rugged MK4 option.
• Features integrated M1913 Picatinny rail sections at the fore, 3, 6, and 9 o’clock.
• Adds M-LOK slots at the 3, 6, and 9 o’clock positions plus the upper 45-degree quadrants.
• Maximum venting at the lower quadrants reduces weight and aids heat dissipation.
• Finished in Desert Dirt Color (DDC).
• Includes Geissele’s proprietary 2.25-inch-long barrel nut.
• Barrel nut design keeps the rail straight and true along its full length.
• Improves accuracy and zero repeatability during disassembly and reassembly.

Frequently Asked Questions

Does this rail include a barrel nut? Yes, it ships with Geissele’s proprietary 2.25-inch-long barrel nut.

What color does this rail come in? Desert Dirt Color (DDC).

Buy the Geissele MK4 Super Modular Rail

Get an ultra-rugged, straight-and-true rail in a Desert Dirt finish. Order it from our Geissele Automatics lineup of AR handguards for fast shipping from our Lubbock, Texas gun shop.