Geissele Automatics MK4 Federal Super Modular Rail M-LOK – 10″


DDC (Desert Dirt Color)
OD Green

Product Description

This is the same rail used to fulfill contracts for the Federal Bureau of Investigation (FBI). Its strength, modularity, and M-Lok compatibility give users the capabilities needed to successfully complete the mission at hand.

The Federal line features an extended rail length of 10″, as well as an extended 6 o’clock Picatinny rail.

These rails are purpose-built and feature integrated M1913 Picatinny rail sections at the fore of the rail in the 3, 6, and 9 o’clock positions. The Picatinny rail on the bottom of the rail, or the 6 o’clock position, is elongated in this version to more comfortably accommodate accessories. Maximum venting for heat dissipation also dramatically reduces the rail’s overall weight, while maintaining its same strong and rigid platform. The MK4 M-LOK rail features M-LOK slots at the 3, 6, and 9 o’clock positions as well as the upper 45° quadrants. This allows the user to keep the weight on the rail system down while keeping the modularity and versatility to attach accessories as necessary.

  • Height: 2.30″
  • Material: 6061-T6 Aluminum.
  • Finish: Type 3 Hardcoat Anodize
  • Length: 10.0″
  • Inner Diameter: 1.35″
  • Outer Diameter (DAQ*): 2.11″
  • SMR MK4 10″ Weight: 10.2oz (11.8oz w/ barrel nut)




Technical Information


6061 Aluminim





Catalog Location

California Prop 65 Warning

WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information visit