[Ensemble] Airosft Single Point Red Dot - OEG [JJ Airsoft] + Front Lens Protector for Single Point Red Dot Sight - [JJ Airsoft] + Rubber Knob Cover...

Beautiful replica. Looks great on XM. Optic fiber is good. I verry miss mounting manual, it took me almost half hour to find out how to attach the older mount and next half hour was total nightmare to mount it together

Hello,
my English isn't very good, so I'll use Google Translate and hope it works properly.

It's a really old-school sight; it's installed on my XM-177. Visually, it's perfect.
The aiming might seem a little confusing at first, but you just need to let your eyes adjust, which in my case was quick.

I tested it this weekend during a game in the woods, and it was great; the red dot is clearly visible even in average light.
Personally, I didn't use the system with the metal brackets, but the one that comes pre-installed in the box.

Absolutely great replica in itself.
I love it, even with its little quirks. That said, there's 3 issues that may bother some people:
1) The light-conveying fiber isn't good at catching ambient light in buildings unless there's a light on or something. Whenever I walked into an area indoors where the front wasn't facing a window or some other light source, the dot was almost impossible to see. I'd wager the real ones had more sensitive fibers?
2) The mount with the metal strips (aka the older one) are a nightmare to assemble, and no guide is provided. I almost stripped one of the threads in the retention cyllinders. Getting that assembled was pretty much a work of luck and I'm planning to never disassemble this.
3) The channel in the older version of the mount mount doesn't actually line up with the iron sights. You can't use them as backup. However, looking through the channel is good enough for aiming in CQB when I can't see the dot in less lit areas indoors.

But this really brought my 1970s tacticool XM177 build together, for which I'm grateful and really happy with this replica.