I’ve a Viridian RFX45 that I bought a few years ago. I’d tried to fit it to the XP Pro back then but there were issues. To install it, I’ve to stack a plate upon a plate. Luckily, the irons will still co-witnesses through the glass (only just — I can even see the dot on the front iron sight). Oh, and I had a devil of a time finding screws to secure the Acro plate to the Fusion plate.
This particular optic is a closed emitter unit. I haven’t been using it, and it’s better than not using an optic, in my opinion. I do like the 407C’s view port size better, though.
UPDATE (10/19/2026): I went to the range yesterday evening and shot just under 100 rounds through the XP Pro. The Acro plate came loose twice (yeah, it had blue threadlocker applied to it 24 hrs before), so I stopped shooting it. I’ll try Vibratite next – hoping that works, but if not, I’ll look into getting some different screws to secure it (the screws are very small and have very little threading – I’d actually anticipated that they would loosen). Better yet, I may just purchase another optic. The RFX45 did extremely well, though, which is a pity that the plate won’t stay secured to the Fusion Firearms RMR plate.
UPDATE (10/24/2026): Instead of continuing to attempt to make this optic work with the Fusion Firearms 2011s, I decided to just get a Holosun. I was thinking on getting another Cyelee Chameleon but those are a bit more than I’m willing to pay (they are $199). Now, I’ve not tried to fit a Holosun to this, but I’m thinking it’ll work better than trying to fit the Viridian. As well, the Holosun I bought is the 407C (I already have one of them on my carry gun). I bought one earlier in the year, at The Gunshop USA for around $160 (before shipping). I checked to see if they still had them at the same price and they did, so I bought another one a few minutes ago. The link for the 407C is here – you’ve to ask for a price via email and they send it to you within five minutes of asking. The total price with shipping is $188, which still undercuts the Cyelee Chameleon price.
UPDATE (10/30/2026): So, I removed the RFX45, then redid the threads with another type of blue threadlocker instead of the cheap threadlocker that I initially used. I let it cure for 3-4 days, and also ensure the screws were tightened using an inch-lb torque wrench. I also used threadlocker on the side-screw of the optic. I then took it to the range yesterday and shot a box of ammo through it. The adapter plate and optic did not move. I believe I’ve solved the issue. HAH! Now I’ve a 407C that will sit in a box for a while as a hot spare. Yes, I could remove the RFX45 and swap in the 407C, but why remove the RFX45 when it’s now solidly mounted? If/when the optic loosens, I’ll switch out the optic.
