Has anyone used one before? It looks like a good and less expensive substitute to the eotech magnifier which is four times as much as the vortex version. Id most likely be using this while on a perimeter, more than likely no further than 75 yards.
http://www.vortexoptics.com/product/vortex-vmx3-red-dot-magnifier
http://www.vortexoptics.com/product/vortex-vmx3-red-dot-magnifier