I have rather enjoyed watching M-LOK & KeyMod proliferate throughout the market with the various accessory manufacturers embracing the specification. The specs, while fantastic, do have potential issues with purely round or octagonal handguard systems. Simply put, those types of handguards often have to have an OD of a certain size to clear barrel nuts and suppressors which can make mounting forward iron sights rather awkward.

The OD of the handguard coupled with common adapters are typically too tall. The rail will sit about 1/8″ to 1/4″ taller than the base receiver, which makes matching irons a pain or when mounting accessories to the 12 o’clock position, sit tall which can interfere with optics and sight picture.

To the relief of geardo’s like me, Arisaka Defense has stepped in with slim rail adapters for both the M-LOK and KeyMod systems. The adapters feature five complete picatinny rails (ideal for folded BUIS) mounting via three M-LOK t-nuts or three “keys” for KeyMod.

Weight is kept to a minimum, with only .7 ounces of 6061 aluminum for the M-LOK version and .6 ounces for the KeyMod version. Both are type III hard-coat anodized and arrive with mounting hardware installed.

Pricing for both is set at $28.00 retail available directly from Arisaka Defense and their dealer network.