Geissele 15" M-LOK MK4 DDC Super Modular Rail 05-315S

Geissele 15" M-LOK MK4 DDC Super Modular Rail 05-315S is the longest option in the MK4 lineup - the ultra-rugged M-LOK rail built with integrated Picatinny sections up front rather than leaning on M-LOK adapters for accessories that really want a hard rail interface.

Machined from 7000-series aluminum and Type III hardcoat anodized in Desert Dirt Color, this Geissele Super Modular Rail MK4 locks onto the receiver through Geissele's proprietary 2.25" barrel nut, which extends surface contact well beyond a standard nut's footprint to keep zero repeatable through disassembly and reassembly. Integrated Picatinny sections sit at 3, 6, and 9 o'clock up front for lights and bipods, backed by M-LOK slots at those same positions plus the upper 45° quadrants everywhere else.

Maximum venting across the lower sections cuts weight without touching rigidity — this Geissele MK4 Rail comes in at 12.8 ounces bare, 15.1 with the barrel nut installed. That's a fair amount of rail for the weight, especially at this length.

Key Features:

• 15" free-float length, full-length Picatinny top rail
• Integrated Picatinny sections at 3, 6, 9 o'clock
• M-LOK slots at 3, 6, 9 o'clock plus upper 45° quadrants
• 7000-series aluminum, Type III hardcoat anodized
• Proprietary 2.25" Geissele barrel nut
• Weight: 12.8 oz bare, 15.1 oz w/ barrel nut
• Height 2.4", inner diameter 1.35", outer diameter 2.11"
• Desert Dirt Color finish

This Geissele MK4 DDC rail gives longer-barreled builds the full accessory real estate the MK4 line offers, without the fit and finish compromises that come with cheaper 15" options - this Geissele Super Modular Rail holds the same standards the whole lineup is built to.