The enclosed emitter, red dot sight market, is getting packed with options. One of those options is the Viridian RFX45. Because it is from Viridian, it uses a green dot, not red, as green is what Viridian is known for. The RFX45 is mainly designed for pistols, but can be used on rifles. I’m mainly going to focus on it as a pistol optic.

As mentioned, the RFX45 is a closed emitter dot style sight. Some people have nicknamed them “mailbox” sights, since they look like a mailbox sitting on top of your pistol. This is due to the square, boxy shape of the sight. The closed emitter sight has some distinct advantages over the open emitter style. For instance, the RFX45’s emitter won’t get dust or moisture on it. So the image of the dot stays clear. Yes, dust and moisture can get on the outside lenses, but this doesn’t affect the emitter itself and is easily cleaned off. I find enclosed style dot sights are easier for me to find the dot. This is due to it being easier to look down a tube, since my eyes find the center of a tube naturally. I know the RFX45 is technically a rectangle, but it still works better for me. To me there are only two disadvantages, and they really are small ones. Enclosed style sights, like the RFX45, can weigh more than open emitter style. The RFX45 only weighs around ¾ oz more than most open reflex sights. The RFX45 is still light enough that, most likely, you won’t have to change recoil springs, I didn’t. The next disadvantage could be their size. You might be more likely to hit it on something. Or, it might be harder to conceal under a shirt. Other than that, mailbox style sights, like the RFX45, are a great sight option.

Most of the closed emitter sights you encounter will have the ACRO footprint, the Viridian RFX45 is no different. The ACRO style footprint is a little unique, in that it is kind of like a mini picatinny rail. This means that you will need an adapter if your slide is not specifically cut for an ACRO. Do not fear, Viridian has different options as to what adapter plate the RFX45 comes with. Either a MOS, RMR, DOCTOR, or a low or high mount. The high mount is to mount it on an AR style rifle. The RFX45 I was sent had the MOS adaptor as the RMR ones were not out yet. I used a Primary Machine plate and it worked just fine. I do like how Viridian uses an “Industry Standard'' mounting platform for the RFX45.

Bottom dot is from the fiber optic front sight.

The Viridian RFX45 is packed with useful features. First, the RFX45 has Instant-On. So whenever the sight senses motion, it turns the green dot on. If it sits for 2 minutes, the dot goes off until it senses movement again. This feature worked flawlessly in the RFX45. I had zero problems with it. Next up is the 50,000 hr battery life. This long battery life is also attributed to the Instant-On capability and its CR2032 battery. The green dot size is listed as 5 MOA which is slightly larger than some others. Since this is a green dot, the 5 MOA dot appeared to be slightly smaller to me. But either way, the 5 MOA dot size worked fine for everything I did with it. The RFX45 has 10 brightness settings, 2 of which are night vision compatible. At the highest setting, the RFX45 can be seen in direct bright sunlight. During my shooting experiences, some in bright sunlight, I could see the green dot just fine.

Window size can play an important role when choosing an enclosed red dot/green dot sight. The Viridian RFX45 has a 24mm wide x 15.5mm tall window size. This window size is wider than most of its competition. Most are 15mmx15mm. As mentioned previously, this window size makes the sight super easy for me to pick up. This includes under recoil, the draw stroke, and transitioning between target to target. The clear green dot probably helps a little with that too. All I can say is that I pick up the RFX45’s dot faster than my open reflex sights.

Being the RFX45 is one of those mailbox style sights, I better explain some about its style. Yes, it’s square. But more on point is that the battery is housed at the top of the optic. So no removing the sight to change the battery. On the left side is a rubber pad with the up/down brightness buttons. The glass has an ever so slight tint to it. I never even noticed the tint, even on darker days. It’s super clear. Speaking of clear, the dot is extremely clear also. I have an astigmatism, and the dot doesn’t star out as much as some of my other green dots. For those of you with normal eyes, you will get a super clear round dot. I mounted the RFX45 to a Grey Ghost Precision slide that was cut for an RMR. Even with an adapter plate, the RFX45 sits level with the top of my slide. This allows me to still use the tall iron sights that are on the pistol.

So, if you are in the market for a “mailbox” style sight, do take a look into the Viridian RFX45. It may cost a little bit more than some others, but you are getting a quality enclosed green dot sight. I used it quite a bit and it never failed me, something I can’t say about the ammo I was using. You get a lot of high end features in the RFX45. You can check it out at Viridianweapontech.com