i recently bought a sightmark holographic sight. it,s small thats why i put it on my 22/45 ruger lite. heres the strange part. once i take it out in the cold, the green no longer works. red still works but green does not. let it warm back up & green can be seen again. did some reading & that is common with green lasers, they don't like the cold, even green laser pointers don't work as well in the cold.