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F4 Defense Adaptive Rail System: M-LOK and Picatinny Rail Combined

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Let’s face it – the existence of various accessory mounting systems is not the most convenient thing in the world. Although you can find all kinds of adapters between M-LOK, KeyMod and Picatinny rails, it is still not too convenient. F4 Defense makes our lives easier by combining two of these mounting systems into one. Their Adaptive Rail System (ARS) is like a Picatinny rail with an M-LOK slots machined into it. Pretty simple and straightforward.

Note the M-LOK slots machined into the Picatinny rail

When mounting a Picatinny rail compatible accessory on the F4 Defense Adaptive Rail System, it works just like any other Picatinny rail. If you install an M-LOK accessory, it sits right on top of the Picatinny rail. The mounting procedure of both systems is not changed. As a side effect of milling M-LOK slots into the Picatinny rail, you also end up having a lighter and a better ventilated handguard.

F4 Defense Adaptive Rail System - M-LOK and Picatinny Combined (2)

Let’s watch the promo video of the Adaptive Rail System.

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F4 Defense has a variety of AR-15 and AR-10 handguards with the Adaptive Rail System. They make full railed handguards with the ARS on all four sides as well as a lighter version with the majority of the side and bottom rails being M-LOK only. They also have different handguard lengths – from 8.3″ to 15.8″ and a couple of more options between those. The prices of different F4 Defense handguards vary from $175 to $235 depending on the type of the handguard, its length and the weapon system it is designed for. Visit the company’s website to find out more about the different options and prices.

F4 Defense Adaptive Rail System - M-LOK and Picatinny Combined (3)

Note the full-length ARS rail on this handguard …

F4 Defense Adaptive Rail System - M-LOK and Picatinny Combined (31)

…and the lightened handguard with ARS only in the front portion of 3, 6 and 9 o’clock rails

These rails are made in the USA and the Adaptive Rail System itself is a patent pending design.

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