Let me say, this is one of the best products we tested out recently. I love the Cosmic bow sight made by Impact Archery. It is the brightest, NON-mechanical sight I've ever used.
The Cosmic has 2 1/2 feet of .030" light-gathering fiber optic wrapped internally in the Cosmic "Ring". Every bit of that 2 1/2 feet gathers all available light and concentrates it in the single pin on the Cosmic sight. To say that it is BRIGHT would be an understatement. I have used several fiber obtic bow sights over the last few years, but never has one been even half as bright as the Cosmic. No matter which sight I used, there was still at least 15-30 minutes of "legal" shooting time left after I could no longer see the pin well enough to shoot. This was especially true when hunting in densely forested areas where the thick forest canopy does not allow much light to reach the ground. With the Cosmic, the situation has now been totally reversed. 90% of the time when testing out the Cosmic, the pin was still bright enough to shoot after I could no longer see the animal well enough to shoot.
In Texas, it is legal to hunt wild feral hogs after dark, and since they are sometimes very nocturnal, we commonly do exactly that - hunt them after dark. I shot one hog using the Cosmic, at least 15-20 minutes after "legal" shooting time for deer had ended. I could still see the pin well enough to make a good shot, and I did. I was extremely impressed. Hunting during a full or close to full moon with no cloud cover, the amount of light given off by the moon has been more than enough to light up the Cosmic adequately for shooting hogs. And when hunting hogs without the benefit of the full moon, I used their "Blue Light" attachment which is a battery-operated soft blue light which lights up the pin like it was daylight.
I took this Texas wild hog well after sunset using the Cosmic bow sight
The frame of the Cosmic is very sturdy, made of aluminum. The Cosmic "Ring" is thick, heavy-duty plastic of some sort, which completely encases the fiber-optic. The fiber optic, where it ends in the sight pin, is also supported very well so as not to be fragile.
The only downside of the Cosmic, for those folks who it would effect, is that it only has a single pin. As bow technology has made higher arrow speeds the norm rather than the exception, more bowhunters are finding it unneccessary to have multiple sight pins. I use my Cosmic to shoot from 0-30 yards, with only a slight change in where I hold on the target. The one pin on the Cosmic IS adjustable with little "hash marks" for different yardages. Most of the hunting I do doesn't allow for the time spent (even just 5-10 seconds) changing the pin to a different yardage, and I don't use a rangefinder anyway, so I just give it my best estimate and shoot for that distance. For those whose hunting situations WOULD allow for the time to move the sight pin, it's quite easily done.
I highly recommend the Cosmic. It's the sight I have on my primary bow for this coming hunting season.
Bright, sturdy, easy set-up
Only one sight pin