I was sitting in the deer stand this morning practicing sighting on a small deer. I was facing the sun and got a lot of glare and remember Leupold sells sunshades. For 40mm scopes, the offer one for pre-2004 and post 2004. Anyone know how to tell the difference? I have a VariX 3 in 3.5-10. Also, should I get the 2" or 4"?