Sights and a real newbie question

[bonzai]

Could someone possibly explain the difference in the following three sights and help me with the advantages and disadvantages of each.
30 mm red dot sight
30 mm 2x red dot sight
red dot open 4 reticle

Thanks in advance
__________________

 

[esheato]

Post a link perhaps?

 

[rcmodel]

A 30mm RD sight has a tube with 30MM lens and no magnification.
A 30mm 2x is the same as the first except 2 power magnification.
An "open 4" appears to be TruGlo's name for the flat screen model with no tube, and no magnification.

I can tell you right up front you don't want the 2x model.
Lots of complaints about excessive parallax with them.
http://www.thehighroad.org/showthread.php?t=288424&highlight=truglo+2x+sight
http://www.thehighroad.org/showthread.php?t=182887&highlight=truglo+2x+sight


rc