I received a Barska brand SWAT Extreme Tactical model scope a while back and have been putting it through the paces.  So far I have found that the factory mounts and flip-up lense covers are sub standard and are not fit for an air rifle.  I have been using this scope on a Savage 10FP .308 and both an AR15 and an AR10.  The glass seems clear enough in average light conditions in an open field and it seems to hold a zero.  At 200 yards it is easy to see both the .308 and .223 holes in a target.  I will be testing it in low light woods conditions soon and making a direct comparison to a Nikon Monarch in these conditions.