I would also like to clarify the difference between and IR and IGR.
The term IR stands for "illuminated reticle" or (illuminated wire reticle). This is where the entire wire reticle is lit up. In most cases this type of illumination causes excessive tube glow because it requires a brighter led to illuminated the entire wire reticle which can and will over power your view, especially on a higher power brightness setting.
The term IGR which is used in the Mueller scopes stands for "illuminated glass reticle" or (illuminated glass etched reticle). This is where a completely different style reticle is used. The reticle is actually adhered to a lens and which ever portion of the reticle the manufacture wants illuminated is etched into the glass. The style of illumination causes virtually no tube glow even on the highest brightness setting. This style reticle will also with-stand more recoil, you would actually have to shatter the lens in order to blow this style reticle out..
Mueller Optics
