XS Sights R3D 2.0 Night Sights for Glock 21 Green
XS Sights
$128.12
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XS Sights
XS Sights R3D 2.0 Night Sights for Glock 21 Green
The XS Sights R3D 2.0 Night Sights for Glock 21 (Green) deliver a second-generation upgrade in tritium sight technology, combining a dual-illuminated front sight with an anti-glare blacked-out rear for lightning-fast target acquisition in any lighting condition.
- Dual-illuminated tritium photoluminescent front sight for bright and low-light performance
- Green photoluminescent Glow Dot ring provides high-contrast aiming reference instantly
- Anti-glare, serrated blacked-out rear sight drives focus to the front sight
- Black nitride surface finish resists corrosion and withstands everyday carry abuse
- DIY install-rated design requires 50% less installation force than previous generation
- Rear sight ledge enables reliable one-handed slide manipulation when needed
Who This Is For
The XS R3D 2.0 is purpose-built for Glock 21 owners who depend on their firearm for everyday carry, home defense, or duty use. Whether you're a seasoned shooter upgrading aging sights or a first-time sight installer looking for a confident DIY fit, these sights offer a significant performance boost over factory options — delivering speed and accuracy from bright daylight to complete darkness.
Specifications
| Brand | XS Sights |
|---|---|
| Model | R3D 2.0 |
| Compatible Firearm | Glock 21 |
| Front Sight | Dual-illuminated tritium photoluminescent |
| Rear Sight | Blacked-out serrated, tritium dot |
| Glow Dot Color | Green photoluminescent ring |
| Surface Finish | Black nitride |
| Installation | DIY-rated, 50% less force required |
| Special Features | Rear ledge for one-handed slide operation |
| Intended Use | EDC, home defense, duty carry |
Frequently Asked Questions
Will the R3D 2.0 sights fit all Glock 21 generations?
The XS R3D 2.0 sights are specifically designed to fit the Glock 21, which uses a standard dovetail cut compatible across Gen 3, Gen 4, and Gen 5 frames. However, always confirm your exact generation and variant (e.g., Glock 21 SF) against XS Sights' compatibility chart before purchase, as subtle dimensional differences can occasionally affect fitment.
How do the tritium and photoluminescent elements work together?
The R3D 2.0 front sight uses a dual-illumination system: the tritium vial glows on its own in complete darkness using a self-powered radioactive gas capsule, while the surrounding photoluminescent (glow-charged) ring absorbs ambient or UV light and re-emits it as a bright green halo. Together, they ensure your sight picture is fast and visible whether you're in a dimly lit room or under full daylight.
Can I install these sights at home without a gunsmith?
Yes — XS Sights rates the R3D 2.0 as DIY installer-friendly, and the second-generation design requires 50% less installation force than the original R3D. Most users can install the sights using a quality sight pusher tool or bench-mounted sight press. A nylon or brass punch and hammer can work for the rear sight, while the front sight typically requires a sight tool compatible with Glock's front sight screw. No gunsmithing experience is required, but having the right tools on hand will ensure a clean, damage-free installation.
