Viridian RFX45 Reflex Sight Put to the Test

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Viridian RFX45 Reflex Sight Put to the Test

Unlike conventional LED optics, the RFX45 uses a green dot and the emitter completely closed within the housing.
Sept. 21, 2023

I got to test Viridian Weapon Technologies’ RFX45 Closed Emitter Green Dot Reflex Sight , which I saw for the first time during SHOT 2023. Unlike conventional LED optics, the RFX45 uses a green dot and the emitter completely closed within the housing.

Viridian Weapon Technologies is an innovator in firearm mounted technologies. They are probably best known for their design of green laser sights. Their research found that green light is easier to distinguish than red light. The science behind it centers on the fact that green lasers trigger a higher number of receptor cells in the human eye.  Although the RFX45 is a superimposed dot, rather than a dot projected on the target, the color improved my ability to acquire and engage. I’m with team green now.

As an optic, it’s a little over-engineered. The outside of this is housed in 6061 hard coated aluminum, with recessed lenses. Because the skeleton of this sight is heavy duty, it may be slightly larger than many other sights. OK, maybe it’s a lot larger.

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When I mounted this sight on my Glock 19, my friend asked me what I was doing with the Yeti.

“My gun sight reminds you of a sasquatch?”

“No, it looks like you put an ice chest on your Glock.”

At the end of our tests, the toughness and design of this optic shone through. For assignments that include hard use, I found the RFX45 to be ideal, despite the Yeti jokes.       

The RFX45 uses the acro mounting footprints, which is low-profile for mounting on a handgun. My model came with plate adapters for clock MOS and RMR systems. It also comes supplied with 2 Picatinny adapters, low and high, allowing the optic to be attached to a carbine. Considering the full protection of the lenses, and a fairly wide field of view, it's a pretty good carbine option.

I put the RFX45 on my carbine, using the high Picatinny adapter for 1/3 Lower Co-witness. Co-witnessing is when the iron sights can be aligned inside the window of the optic. It is a way of insuring that if one sighting system fails, another is immediately available.  The adapter raised the sight off the rail to a comfortable cheek weld level. The RFX45 gives the shooter a reflexive non-occluded sight picture with zero parallax issues.

I finally settled the RFX45 on my Glock 17, which has a Lone Wolf slide with an  RMR footprint. The RMR to ACRO plate supplied by Viridian is low profile. If I had suppressor height sights, co-witnessing height would be perfect.

The RFX45 mounting kit came with several screw sets of various lengths.  It mounted cleanly, and, at that time, I thought I was in business. However, I had made a rookie mistake, installing screws that were slightly too long. My folly locked up the gun completely, and I was fortunate to have gunsmith Rick Maccia on the range with me. He came equipped with a Fix It Sticks The Works gunsmith toolkit (

The Works toolkit is a complete driver set, which also has specialized gun tools. Rick had the version that has the All-in-One Torque Driver, which is essential for installing optics correctly.  For Agency armorers, it is the ideal tool setup for range days.

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Gunsmith and retired SRO Rick Macchia Had to fix Lindsey's gun on the range with his Fix It Sticks. this is a toolkit that every law enforcement armorer should own.

Rick had my Glock up and running in no time. I began sighting in the optic. My first group was close to the X, so it took no time to sight the RFX45.

The windage adjustments on the RFX45 are on the top rear corner of the right side of the optic. I used the supplied tool to bring the bullet impact to zero. I don’t know the specs, but the adjustments were fine for a handgun sight, perhaps .5 MOA or so. There is 90 MOA of adjustment, which is about double the adjustment of some optics.

The elevation adjustment is on the top, right next to the battery compartment. That’s right: The battery cover is on the top of the optic, which means that one can swap it without changing any adjustments. Also, the battery life is astronomical. Viridian specs it at 50K hours for a CR 2032 battery, which means that it can be left on all the time and forgotten. Since the RFX45 is an INSTANT-ON optic, it doesn't use any battery if the product is just sitting still. When it is activated by the built in motion sensor, it maintains its latest settings.

Like most pistol sight optics, the field-of-view is unlimited. The  green dot intensity adjustment is on the left side of the case. It has a raised index line and tactile clicks that allow adjustment without looking. There are eight visible and two night vision settings.

When it comes to optics for steering firearms, coatings are distinguish the better products.  I found the coatings to be outstanding on the RFX 45. The window closest to the shooter is hydrophobic and antireflective. I found that this glass was also fingerprint resistant. Of course, my inner klutz came out when I grabbed my gun and smeared my fingerprints all over both lenses. It wipes down to a brand-new appearance using the included microfiber cloth.

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This is Lindsey's first group, 4 shots at 10 yards, after mounting the RFX45. It took only 5 rounds to sight it.

It was dusty during our range sessions. I blew the lenses off a few times, and washed the lenses off once. The coatings can handle some abuse. Just for clarification: In dusty conditions, always blow off a lens before wiping.

When I inspected the optic later, it didn’t have water spots or scratches. When I use an optic, I tend to bang it a bit when doing immediate action (stoppage) drills. I have a habit of getting the side of my hand on the lenses. On some optic products, my fingers contact the buttons, changing the settings. I’m hard on optics, unapologetically. The RFX45 controls are placed more to my liking, and its great to have an optic that has skin like a Tony Stark creation.

The RFX45 manual recommends 3-5 round groups to sight it in. It only took me 5 rounds altogether. I ran some simple drills with my RFX45, testing to see how quickly my eye could align a shot.

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The green dot stands out on just about any background, including green foliage. Viridian uses a green dot because it activates more photoreceptors than a red one.

During the rest of my shooting sessions, the RFX45 always maintained its zero. The INSTANT-ON feature is kind of like your refrigerator door. It is completely unnoticeable and seamless, and one forgets about it. Even drawing from my nightstand in a completely dark room could not fool it, and it switched on faster than I could get the gun up.

At 1.73 OZ, the RFX45 is slightly heavier than other products, but the glass protection is worth it. The weight is not noticeable on duty sized guns.

Mounted on my Glock 17, the RFX45 needs plenty of clearance in a duty holster.  It will not fit under some covered optic holsters, especially ones with hoods. Your mileage may vary here.

The RFX45 is a fully enclosed optic designed for rough duty, and hard handling. It is capable of any duty assignment that calls for a “mounted Yeti”. MSRP is $459, but I have seen it for significantly cheaper.

About the Author

Lindsey Bertomen is a retired police officer and retired military small arms trainer. He teaches criminal justice at Hartnell College in Salinas, California, where serves as a POST administrator and firearms instructor. He also teaches civilian firearms classes, enjoys fly fishing, martial arts, and mountain biking. His articles have appeared in print and online for over two decades. 

Published at: 11-16-2023


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