Lmao, I have never heard anything bad about those and someone modified it to be better, seems that sight has useful info, have found a few thinks taking me there.
It's just another optic (probably a magnifier) that is looking into the ocular of the PLRF-10. That means it's not doing anything to the IR laser beam (like reducing divergence), but is there to help the user see the image better (probably at longer distances since the PLRF-10 is only 6X or so). I would think that a $3 pair of magnifying glasses from K-Mart might help and be a simpler solution! Must be an engineer!!
"I have been using the PLRF 10 for several weeks now and it is just incredible. The only drawback was the low magnification sometimes would not allow sure alignment on a distant target like a deer in a brush patch across a canyon. I took a 2x multiplier from Swarovski and built this mount to quick detach from my tripod. I now have enough magnification to confidently place the crosshairs on the animal and it absolutly rocks."