Developed and designed by Magpul, the M-LOK system utilizes a series of slots by which you can mount your custom AR parts, accessories, and attachments. Magpul offers licenses to anyone wishing to make accessories to ensure that their quality matches that of the handguards they produce. The result is a high-quality and durable rail system that offers rifle owners a flexible platform to attach parts too. US SOCOM forces tested the M-LOK rail system and found them to be versatile and effective, keeping their accessories securely mounted to the handguard.
You can find custom AR parts, add-ons, and handguard accessories for M-LOK AR rail systems at AR Customs.