Reptilia RMU Magnifier Riser 0.39" for 3x & 6x Magnifiers
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Fits 3x and 6x magnifiers in their original Picatinny mounts, on any M1913 Picatinny rail. Adds a fixed 0.39in (9.9 mm) of height to align a magnifier with a red dot at 1.93in. Not a replacement magnifier mount, and not the same part as the 0.625in RMU optic riser.
Not sure it fits your rifle? Ask us before you order
The Reptilia RMU Mount 0.39in is a Picatinny riser for magnifiers, lifting a 3x or 6x magnifier in its original mount so its optical centre lines up with a red dot sitting at 1.93in.
Your dot is at 1.93in and your magnifier is at 1.54in. This is the 0.39in that closes the gap.
Most 3x and 6x magnifiers ship in a flip-to-side mount built around the older 1.54in sightline. Put one behind a red dot at 1.93in and the two no longer share an optical axis — you get a partial picture, or you tip your head to find the centre. Reptilia's answer is a dedicated riser that raises the magnifier and its own mount by exactly the difference.
It is machined from billet 7075-T6 aluminium with a Milspec Type III hard anodised finish and weighs 51 g (1.8 oz). This is not the same part as Reptilia's 0.625in RMU riser, which exists to raise a whole holographic sight — different lift, different job. Made in the USA.
Fits a 3x or 6x magnifier in its original Picatinny mount, on any M1913 Picatinny rail behind a red dot mounted at 1.93in. It raises the magnifier and its own mount together — it does not replace the magnifier mount. Pair it with any of Reptilia's 1.93in DOT Mounts, such as the Aimpoint Micro, Trijicon RMR/SRO or Holosun AEMS versions. If what you want to raise is a whole holographic sight with an integral base, the RMU Mount 0.625in is the other part in this family.
| Platform | AR-15 / M4 |
|---|---|
| Fits | 3x and 6x magnifiers in their original Picatinny mounts, on any M1913 Picatinny rail |
| Type | Magnifier riser — adds 0.39in (9.9 mm) of height |
| Material | Billet 7075-T6 aluminium |
| Finish | Milspec Type III hard anodised — Black |
| Weight | 51 g (1.8 oz) |
| Mount interface | M1913 Picatinny, rail on top |
| Made in | USA |
| Brand | Reptilia |
| MPN | 100-291 |
One part, one job: put the magnifier back on the dot's axis. Order the RMU Mount 0.39" 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, Scope Mounts & Optic Risers or browse all Reptilia.
| Platform | AR-15 / M4 |
|---|---|
| Fits | 3x and 6x magnifiers in their original Picatinny mounts, on any M1913 Picatinny rail |
| Type | Magnifier riser — adds 0.39in (9.9 mm) of height |
| Material | Billet 7075-T6 aluminium |
| Finish | Milspec Type III hard anodised — Black |
| Weight | 51 g (1.8 oz) |
| Mount interface | M1913 Picatinny, rail on top |
| Made in | USA |
| Brand | Reptilia |
| MPN | 100-291 |
| Category | Optic Mount |
| Barcode | 850053448652 |
£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.
Because most magnifier mounts were designed around the older 1.54in sightline, and red dot mounting has moved up to 1.93in. If the dot is higher than the magnifier, the two optical axes no longer meet and you see part of the picture or none of it. The 0.39in difference is exactly what this riser adds back.
Yes. The riser goes between the rail and your magnifier's own mount, so the flip-to-side mechanism, the height adjustment and everything else about your magnifier setup carries over. You are raising the assembly, not replacing part of it.
No, and they are not interchangeable. This one lifts a magnifier by 0.39in to match a 1.93in dot. The <a href="/products/reptilia-rmu-optic-riser-0-625">0.625in RMU Mount</a> lifts a whole holographic sight — EOTech, Vortex AMG UH-1, Sig ROMEO8T — that cannot be taken off its own integral base. Different heights, different problems.
Reptilia publish it for 3x and 6x magnifiers generally, because it works on the mount rather than on the magnifier. What matters is that your magnifier's mount clamps to Picatinny and that your dot is at 1.93in. If your dot is at some other height, this riser will not put the two on the same axis.
Optic mounts are sent 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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