Daniel Defense MK18 RIS II Quad Rail for AR-15
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Fits AR-15/M4 upper receivers on the MK18 pattern, including UK straight-pull AR-15 builds. Carbine-length gas. Rail length 9.55" (243 mm), inside diameter 1.15" (29 mm) — check the gas block profile. No integrated sling swivel attachment point; add a rail-mounted QD attachment point separately.
Not sure it fits your rifle? Ask us before you order
The Daniel Defense MK18 RIS II is a free-float quad Picatinny handguard for AR-15 and M4 rifles, built to the USSOCOM SOPMOD II pattern and bolting on through the six-bolt Bolt-Up System.
The MK18 rail as SOCOM specified it — Mil-Spec 1913 on all four faces, two-piece, and free-floating the barrel underneath.
Daniel Defense built the Rail Interface System to USSOCOM's requirements for the SOPMOD II programme, and the MK18 RIS II is the 9.55" version of it. Every face is Mil-Spec 1913 Picatinny, so lights, lasers, foregrips and pressure pads clamp directly wherever they are wanted with no adapters and no rail sections. The upper rail platform is uninterrupted, and the whole assembly free-floats the barrel for accuracy.
The two-piece design is the part that came from the programme: with the lower rail section removed, an M203 grenade launcher can be attached without additional parts and without special tools, because everything needed is integrated into the rail itself. Construction is aircraft-grade 6061-T6 aluminium with Grade 8 military-specification fasteners, finished in Mil-Spec Type III hard-coat anodising in FDE or Black.
This is a different generation and a different attachment system from the RIS III. RIS II is quad Picatinny; RIS III is M-LOK. Both use the same battle-tested six-bolt Bolt-Up System, and Daniel Defense made them cross-compatible, but the accessories you already own decide which one belongs on your rifle. On a UK straight-pull AR-15 the appeal of a quad rail is the same as it ever was: a hard mounting point exactly where you want one, on a tube that does not move.
Fits AR-15/M4 upper receivers on the MK18 pattern, including UK straight-pull AR-15 builds, and mounts through the six-bolt Bolt-Up System onto its steel barrel nut. Rail length is 9.55" (243 mm) and Daniel Defense specifies a carbine-length gas system; inside diameter is 1.15" (29 mm), which is tighter than the RIS III, so check your gas block profile before ordering. Unlike the RIS III, this rail has no integrated sling swivel attachment point — add a rail-mounted one such as the Daniel Defense Rail Mount QD Swivel Attachment Point, which comes with its swivel. If you would rather have M-LOK than quad rail, the Daniel Defense RIS III M-LOK Handguard is the current generation.
| Platform | AR-15 / M4 |
|---|---|
| Fits | Mil-Spec upper receivers, carbine-length gas; steel barrel nut for the Bolt-Up System |
| Type | Free-float two-piece quad Picatinny handguard, SOCOM SOPMOD II pattern |
| Material | 6061-T6 aircraft-grade aluminium |
| Finish | Mil-Spec Type III hard-coat anodised, Black or FDE |
| Weight | 14.1 oz (400 g) |
| Length | Rail length 9.55" (243 mm) |
| Mount interface | Mil-Spec 1913 Picatinny on all four faces; six-bolt Bolt-Up System |
| Brand | Daniel Defense |
| MPN | 01-004-08020-011 · 01-004-08020-006 |
Quad rail, SOCOM pattern, free-floated. Order the Daniel Defense MK18 RIS II today — imported from the USA with all duties paid by us and dispatched tracked from the UK in 7–10 business days, with nothing to pay on delivery.
Explore more: AR-15 Parts & Accessories or browse all Daniel Defense.
| Platform | AR-15 / M4 |
|---|---|
| Fits | Mil-Spec upper receivers, carbine-length gas; steel barrel nut for the Bolt-Up System |
| Type | Free-float two-piece quad Picatinny handguard, SOCOM SOPMOD II pattern |
| Material | 6061-T6 aircraft-grade aluminium |
| Finish | Mil-Spec Type III hard-coat anodised, Black or FDE |
| Weight | 14.1 oz (400 g) |
| Length | Rail length 9.55" (243 mm) |
| Mount interface | Mil-Spec 1913 Picatinny on all four faces; six-bolt Bolt-Up System |
| Brand | Daniel Defense |
| MPN | 01-004-08020-011 · 01-004-08020-006 |
| Category | Handguard |
| Barcode | 852548002813 |
£5 tracked UK delivery on every order via Royal Mail Tracked 24. Our products are ordered in from the manufacturer rather than held in UK stock, so please allow 7 to 10 business days (Monday to Friday, excluding bank holidays) from the date of your order for it to reach you. Tracking details are emailed on dispatch. UK delivery only.
You have 30 days from receiving your order to cancel it for any reason, then 14 days to send it back unused and in its original packaging. Faulty, damaged or incorrect items are replaced or refunded and we cover reasonable return postage. Refunds go back to your original payment method within 14 days of receiving the return.
No. The MK18 RIS II is quad Picatinny — Mil-Spec 1913 rail on all four faces, the SOCOM SOPMOD II pattern. The <a href="/products/daniel-defense-ris-iii-m-lok-handguard">RIS III</a> is the later generation and uses M-LOK at seven positions instead of side and bottom rails, which makes it lighter and slimmer. They share the six-bolt Bolt-Up System and Daniel Defense made the two ranges cross-compatible, but the attachment interface is completely different, so your existing accessories decide which one you want.
That came from the USSOCOM requirement. The lower rail section removes, which allows an M203 grenade launcher to be attached without additional parts and without special tools, because the necessary components are built into the rail itself. For a civilian build it simply means the bottom rail can come off.
Inside diameter is 1.15" (29 mm), which is tighter than the RIS III's 1.34". A low-profile gas block will pass; a standard front sight base will not. Measure before ordering, and remember the rail must clear the block along its whole 9.55" length.
Not directly — unlike the RIS III, this rail has no integrated sling swivel attachment point. Because every face is Picatinny you can clamp a rail-mounted sling attachment anywhere along it; the <a href="/products/daniel-defense-rail-mount-qd-swivel-attachment-point">Daniel Defense Rail Mount QD Swivel Attachment Point</a> is the matching part and it includes the swivel.
Handguards are dispatched from the United Kingdom with £5 tracked UK delivery in 7–10 business days, and you'll get tracking by email when it ships. If a part turns out to be the wrong fit, see our returns policy or <a href="/pages/contact">contact us</a> and we'll help sort it.
7 to 10 business days from the date of your order. Every order is sent Royal Mail Tracked for a flat £5 and you receive tracking details by email when it is dispatched.
Yes. We list only genuine parts and optics from the brands shown, ordered in from the manufacturer for your order.
Compatibility notes on this page come from the manufacturer. If you are unsure, email us with your make and model before ordering and we will check rather than guess.
Yes. Bundle & Save applies automatically in your basket: 5% off when you buy 2 items, 10% off at 3 items and 15% off at 4 or more. It works across the whole range, so you can mix and match, and there is no code to enter.
Yes — you have 30 days from delivery to cancel for any reason, as long as the item is unused and in its original packaging. See our returns policy for the details.
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