Make sure you read the EOTech - 1 page on the refund program.
I upgraded my EoTech to an Exps2-2.
The reticule is composed of a 65 MOA circle and 2 aiming dots. These dots are calibrated for the ballistic drop of .223 caliber ammunition.
The flip up iron sights cowitness perfectly with this model.
Controls on the left side control the reticule brightness.
Controls on the right side are used to move the reticule for zero. One click is ½" at 100 yards (½ MOA).
Notice the transverse battery cover.
The Exps2-2 uses a quick detach lever instead of the large screw on the 557 I used before.