M-LOK

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M-LOK
Type	Attachment System
Place of origin	United States
Production history
Designer	Magpul Industries
Designed	2007–2014
Produced	2014–present

M-LOK, for Modular Lock, is a firearm rail interface system developed and patented by Magpul Industries. The license is free-of-charge, but subject to an approval process.

M-LOK allows for direct accessory attachment onto the "negative space" (hollow slot) mounting points, and is a competing standard to VLTOR's open sourced KeyMod system for replacing the ubiquitous Picatinny rail in some applications.^[1] Compared to the Picatinny rail system, both M-LOK and KeyMod enable the user to have a slimmer, lighter, smoother and more fenestrated handguard/fore-end with accessories & gadgets mounted only where needed, Whereas a Picatinny handguard typically will have whole length rail slots, resulting in heavier weight, bulkier handguard with sharp edges not user friendly, and poorer barrel ventilation increase the speed of overheating.

The M-LOK system can be seen as an evolution of the Magpul Original Equipment (MOE) system, but the two are not fully compatible. Though newer M-LOK accessories can be used on older MOE slot handguards if an adaptor plate is used, there is no adaptor available for using older MOE accessories on the newer M-LOK handguards.